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International Law and the Use of Force, 4th Edition by Gray, Christine (15th February 2018)

5 The use of force against terrorism: a new war for a new century?

From: International Law and the Use of Force (4th Edition)

Christine Gray

From: Oxford Public International Law (http://opil.ouplaw.com). (c) Oxford University Press, 2015. All Rights Reserved.date: 14 July 2020

Terrorism — Self-defence

(p. 200) The use of force against terrorism: a new war for a new century?

The US invasion of Afghanistan in response to the massive terrorist attacks on the World Trade Center and the Pentagon on 11 September 2001 (hereafter 9/11) led to a fundamental reappraisal of the law on self-defence.1 The US response to 9/11 was to announce ‘a different kind of war against a different kind of enemy’—a global war on terrorism. It continues this war today, not just in Afghanistan but through its targeted killings against suspected members of Al Qaida and its affiliates in Pakistan, Yemen, and Somalia.2 Many writers now argue that 9/11 and subsequent state practice have changed the law on self-defence, but the legal situation is not so clear-cut. More recently the rise of ISIS in Iraq and Syria, and the military response by the USA and other states since 2014, have given rise to renewed debate about the scope of self-defence.

Responsibility for 9/11 was quickly attributed to the Al Qaida terrorist organization led by Osama bin Laden which had been responsible for several earlier terrorist attacks on US targets dating back to 1993.3 The immediate international reaction was one of impressive unity among governments. The UN Security Council and General Assembly passed unanimous resolutions condemning the terrorist attacks;4 Security Council Resolution 1368 (2001) implicitly affirmed the right of self-defence in response to terrorist attacks for the first time. NATO invoked Article 5 of its treaty for the first time in its history and declared that (p. 201) the attack on the USA was an attack on all member states and that they were prepared to act in collective self-defence.5 The OAS also invoked collective self-defence;6 Russia, China, and Japan all gave support to military action.7 Only Iraq directly challenged the legality of the military action.8

The USA demanded that the Taliban regime in Afghanistan close Al Qaida terrorist training camps in Afghanistan, surrender Osama bin Laden and other members of Al Qaida, and open Afghanistan to US inspections. But the Taliban refused.9 The USA with the military assistance of the UK, and pledges of military support from France, Germany, Australia, Canada, and others, began Operation Enduring Freedom in Afghanistan on 7 October 2001.10 At the start of their military action both the USA and the UK wrote to the Security Council under Article 51, asserting that they were acting in individual and collective self-defence.11 Although NATO had indicated its willingness to act in collective self-defence, the USA preferred not to act through NATO. Nevertheless, many member states had forces directly involved in Operation Enduring Freedom at some stage. The EU declared its ‘whole-hearted support for the action that is being taken in self-defence in conformity with the UN Charter and the UN SC Resolution 1368’.12 This operation continued until the end of 2014; it was then replaced by a further US counter-terrorism operation in Afghanistan, Operation Freedom’s Sentinel.13

It is not clear whether these events brought about a radical and lasting transformation of the law of self-defence, or whether their significance should be narrowly construed in that Operation Enduring Freedom was essentially a one-off, a response to a particular incident based on Security Council affirmation and (almost) universal acceptance by states. Even in the immediate aftermath of 9/11 there was a certain lack of clarity as to the exact scope of the right to use force in self-defence against terrorism and as to whether such a right could be invoked unilaterally. Radically opposing versions of the significance of 9/11 and Operation Enduring Freedom are possible. The operation against Afghanistan can (p. 202) be interpreted as a wide or a narrow precedent in the development of the law on the use of force. On the narrowest view, self-defence would be limited to the situation where there had been an actual massive terrorist attack on a state’s territory, where there was a continuing threat of global terrorism from those responsible and where the response was directed against the organization directly responsible in a state which was complicit in the attack; and then only after the Security Council had determined the existence of a threat to international peace and security; and where the Security Council had asserted a right of self-defence, even if not in the operative part of the resolutions. In the case of Afghanistan, Security Council Resolutions 1368 (2001) and 1373 (2001) could be cited as crucial by states explaining their willingness not to condemn the US action.14

In contrast, a wide view of the precedential significance of Operation Enduring Freedom might be asserted whereby states are now free to act in self-defence against the threat of any sort of terrorist attack on their territory or their nationals abroad, even in the absence of any Security Council resolution, and even where the state against whose territory the action is taken had no involvement in any sort of support for the terrorists. Certain writers now claim that subsequent state practice, including that by Israel in Lebanon and Gaza, by Ethiopia in Somalia, and by Turkey in Iraq, has confirmed the precedential effect of 9/11 in expanding the right of self-defence.15 When Western states intervened in the conflict in Syria from 2014 they acted in apparent concert to put forward a wide doctrine of self-defence against ISIS.16

Pre-9/11 Practice

The invocation of self-defence to justify the use of force in response to terrorist attacks had been made by only a few states before 9/11. The USA and Israel had invoked Article 51 to justify the use of force in response to terrorist attacks on nationals abroad, but many regarded their use of force as going far beyond the bounds of this provision. Force was used in response to past terrorist attacks by Israel in 1968 against Beirut and in 1985 against Tunis and by the USA against Libya in 1986, Iraq in 1993 and Sudan and Afghanistan in 1998. In all these episodes force was used against the state allegedly harbouring the terrorist organization responsible. Israel and the USA used language that combined claims to be acting in response to past attacks and to deter future attacks.17

(p. 203) The first instance was the attack by the Israeli air force on Beirut airport in December 1968; Israel attempted to justify this action as a response to the earlier terrorist attack on an Israeli plane in Athens airport. It said that Lebanon had permitted Arab terrorist organizations to set up their headquarters in Beirut and to maintain training bases in Lebanon, thus officially encouraging warfare by terror against Israel. The Lebanese government had assumed responsibility for the activities of terror organizations. The attack on the Israeli civil aircraft at Athens airport had violated the ceasefire between Israel and Lebanon, and Israel was entitled to exercise its right of self-defence. The Security Council unanimously condemned the Israeli action in Resolution 262 (1968). It is striking that although the USA joined in the condemnation it made a point of explaining that it did so only because Lebanon had not in fact been responsible for the terrorist attack on Athens airport and the Israeli action was not proportionate; it accepted the principle on which the Israeli action was based. A state subject to continuing terrorist attacks could respond by appropriate use of force to defend itself against further attacks; this was an aspect of the inherent right of self-defence recognized in the UN Charter.18

This was not the view of the other states in the Security Council in 1968, but it has been repeated by the USA and Israel in later episodes. Israel in its 1985 attack on Tunis claimed that it was acting against the Palestine Liberation Organization (PLO) headquarters in response to terrorist attacks on Israelis abroad by Palestinians. It also claimed that Tunisia had a duty to prevent such attacks being carried out from its territory. Israel said that it was acting in self-defence and the USA in the Security Council debate accepted this argument. But the other member states did not agree and the action was vigorously condemned as an act of armed aggression against Tunisia’s territory in flagrant violation of the UN Charter by 14–0–1 in Resolution 573 (1985). For the other member states the Israeli conception of self-defence was very far from that in international law.19

The USA itself undertook this type of action in 1986 against Libya. In response to terrorist attacks against US citizens abroad for which it said Libya was responsible, US aircraft, flying from bases in the UK with the support of the UK government, attacked targets in Tripoli. The USA reported the action to the Security Council as self-defence under Article 51; its action was a response to past terrorist attacks on nationals and also taken to deter such attacks in the future. Most states rejected this claim saying that self-defence should be narrowly interpreted (p. 204) and could not be pre-emptive. However, the UK and France joined the USA in vetoing the resolution condemning its action.20 The UK accepted that ‘the right of self-defence is not an entirely passive right’; it was within the inherent right of self-defence to try to turn the tide of terrorism and to discourage further attacks.21

The USA used the same wide doctrine of self-defence to justify its action in its response to the alleged assassination attempt on ex-President Bush by Iraqi agents in Kuwait in April 1993. The USA responded in June 1993 by firing missiles at the Iraqi Intelligence Headquarters in Baghdad. It again invoked Article 51 in its letter to the Security Council. The response of the Security Council showed considerable sympathy with the USA and some commentators have tried to argue that this marked the emergence of a new rule of international law allowing such actions in response to terrorism. But in the Security Council it was only Russia and the UK which offered express support for the US legal argument.22 The UK took the line that force may be used in self-defence against threats to one’s nationals if the target continues to be used in support of terrorist acts against one’s nationals and there is no other way to respond.23 Several states expressed concern, although only China actually condemned the US action. Other states generally said that they understood the US action; thus France said that it ‘fully understands the reaction of the US’. This falls some way short of support for the legality of the US action.24

Similarly, when the USA responded to terrorist attacks on its embassies in Kenya and Tanzania in August 1998 by missile attacks on a terrorist training camp in Afghanistan and a pharmaceutical plant in Sudan, the response of the rest of the world was generally muted. The USA said that the camp had been used by the Al Qaida organization to support terrorism and that the pharmaceutical plant produced chemical weapons for terrorist activities. It reported its actions to the (p. 205) Security Council under Article 51: the USA had exercised its right of self-defence in responding to a series of armed attacks against US embassies and nationals; it said that it was acting in response to those terrorist attacks and to prevent and deter their continuation. Its attacks were carried out after repeated efforts to convince Sudan and the Taliban regime in Afghanistan to shut down the terrorist facilities. The targets struck and the timing and method of attack used were designed to comply with rules of international law, including the rules of necessity and proportionality.25 Sudan requested a meeting of the Security Council but the issue was not put on the agenda and there was only a very brief meeting with no action taken. There were condemnations of the US use of force by Arab states, the Non-Aligned Movement, Pakistan, and Russia. As before, those who refrained from condemnation or expressed support were careful not to expressly adopt the US doctrine of self-defence.26

All these episodes were justified by the states using force as self-defence, but on the basis of the explanations given by Israel and the USA themselves the actions look more like reprisals, because they were punitive rather than defensive. Even if the actions were aimed at those actually responsible for the terrorist attacks, and even if the response could be accepted as proportionate, it is difficult to see how the use of force was necessary, given that the attacks on the nationals had already taken place. One problem for the USA and Israel is that all states agree that in principle forcible reprisals are unlawful.27 The General Assembly made this clear in the Declaration on Friendly Relations and the Resolution on the Inadmissibility of Intervention. The Security Council also passed Resolution 188 in 1964, in response to a British attack on Yemen, but declaring in absolute terms that it condemned reprisals as incompatible with the purposes and principles of the UN. This universal agreement that reprisals are not lawful led Israel and the USA to try to stretch the meaning of Article 51. Other states were not prepared formally to condemn the USA for its attacks on Baghdad, Afghanistan, and Sudan, but they did not accept the US legal argument. Only Russia and the UK were (p. 206) prepared openly to support the legality of the US action in 1993. Russia later abandoned its brief moment of enthusiasm and returned to a critical approach; even the UK, as so often the main supporter of the USA, took an ambivalent position in 1998. Failure to condemn the USA should be taken to indicate sympathy and understanding rather than acceptance of a legal doctrine which destroys the distinction between reprisals and self-defence and which the USA would never contemplate being used against itself.

The Impact of 9/11

Therefore, before 9/11 it was clear that the right to use force in self-defence against terrorist attacks was very controversial. But the almost universal support of states for a US right of self-defence in response to 9/11 may be seen as raising the question whether there has been a significant change in the law. For some this was just a continuation of the existing wide right of self-defence; for others it was a new right based on a re-interpretation of Article 51 of the UN Charter or the evolution of a customary international law right; for others the acceptance was merely political and did not serve to create a wider right of self-defence. After 9/11 it seemed that the members of the Security Council were willing to accept the legality of action in self-defence in response to the terrorist attacks on the World Trade Center and the Pentagon as they unanimously passed Resolution 1368 on 12 September and Resolution 1373 on 28 September 2001. These both assert in the preamble that the Security Council is ‘determined to combat by all means threats to international peace and security caused by terrorist acts’ and that it recognizes ‘the inherent right of individual or collective self-defence in accordance with the Charter’.

Although some expressed doubt as to whether these resolutions actually support self-defence against terrorist actions, because the reference to self-defence is made in general terms in the preamble rather than the operative part of the resolutions and the language is that of ‘threat to international peace and security’ rather than ‘armed attack’ under Article 51,28 it seems arguable that the members of the Security Council were in fact willing to accept the use of force in self-defence by the USA in response to the terrorist attacks. The reference to self-defence in the preamble is of greater significance than might appear taken in isolation, because the Security Council does not commonly make any express reference to the right of self defence in its resolutions. That is, it seems from the international response to 9/11 that there could, under certain conditions, be a right of self-defence (p. 207) against non-state actors for terrorist attacks. But there are difficulties in establishing the exact scope of this right.

The concept of armed attack after 9/11

One of the fundamental questions arising out of 9/11 is whether the concept of ‘armed attack’ in Article 51 has undergone a revolutionary change so that it now extends to attacks by non-state actors even if there is very little or no state complicity. It is true that Article 51 does not specify that an armed attack must be by a state, though the Charter framework was clearly a response to the Second World War and was directed at inter-state conflict.29 Even if there could hypothetically be an armed attack in the absence of state complicity in that attack, the question of the permissible response is much more problematic.30 For many states and commentators the concept of self-defence against non-state actors was unacceptable before 9/11. Few were willing openly to support a right to use force against a state where the terrorists operated or were present in the absence of the complicity of that state in the terrorist acts.31 The test generally accepted by states was that in the Definition of Aggression, taken by the ICJ in the Nicaragua case as applicable to the concept of armed attack: that the use of force by individuals constituted an armed attack only when there had been a ‘sending by or on behalf of a state of armed bands, groups, irregulars or mercenaries, which carry out acts of armed force against another State of such gravity as to amount to acts of aggression, or its substantial involvement therein’.32

After 9/11 President Bush announced that the USA would make no distinction between terrorists and those who ‘harboured’ them, and that it would treat any nation that harboured terrorists as a hostile regime.33 The Joint Resolution of Congress authorizing force, the Authorization for Use of Military Force Against Terrorists (AUMF), authorized ‘the President to use all necessary force against those nations, organizations or persons he determines planned, authorized, committed, or aided the terrorist attacks … or harboured such organizations of persons’.34 This has been seen by some as a widening of the right of self-defence. But the USA did not use this language in its letter to the Security Council under (p. 208) Article 51; here it said that it had ‘obtained clear and compelling information that the Al-Qaeda organization, which is supported by the Taliban regime in Afghanistan, had a central role in the attacks … The attacks on 11 September 2001 and the ongoing threat to the United States and its nationals posed by the Al-Qaeda organization have been made possible by the decision of the Taliban regime to allow the parts of Afghanistan that it controls to be used by this organization as a base of operation.’ Despite efforts by the international community the Taliban regime had refused to change its policy. From the territory of Afghanistan Al Qaida continued to train and support terrorists who target US nationals and interests in the USA and abroad.35

The UK argued that Al Qaida was something between a traditional terrorist organization and a state. Osama bin Laden and Al Qaida had been able to commit the atrocities because of their close alliance with the Taliban regime which allowed them to operate with impunity in pursuing their terrorist activity.36 In its letter to the Security Council the UK said that the military action was directed against Osama bin Laden’s Al Qaida terrorist organization and the Taliban regime that was supporting it.37 After the event the UK retrospectively claimed that their use of force against Al Qaida and the Taliban in Afghanistan had been undertaken on the basis of a right of self-defence against those who planned and perpetrated large-scale terrorist acts and those who ‘harboured’ terrorists.38

Both states thus left uncertain what degree of involvement, if any, by Afghanistan was necessary to justify the use of force against its territory. Commentators disagree on their interpretation of the facts and of the significance of the language of the USA and the UK. Some argued that there has been a change in the law to widen it to allow self-defence against states harbouring terrorists;39 others say that such an attempt to widen the law would be impermissible;40 others claim that on the facts the relationship between Al Qaida and the Taliban regime was sufficiently close to come within the traditional requirements as set out in the Definition of Aggression, even though the USA had used the language of harbouring.41 In this particular case the Security Council had passed repeated resolutions (p. 209) strongly condemning the continuing use of Afghan territory for the sheltering and training of terrorists and planning of terrorist acts, deploring the fact that the Taliban continued to provide a safe haven to Osama bin Laden and demanding that the Taliban regime stop providing sanctuary and training for international terrorists and their organizations.42 Considerable uncertainty thus remained on this long-standing controversy as to the definition of armed attack.

As was shown in Chapter 4, the ICJ in the Wall Opinion (2004) did not make a clear pronouncement on these questions as to whether there can be an armed attack by a non-state actor and as to what would be the permissible response to such an attack in self-defence.43 Many interpret its brief paragraph on Article 51 as expressly ruling out self-defence against non-state actors, but it is open to doubt whether Court took such a categorical position.44 What is clear is that the Court adopted a restrictive interpretation of Security Council Resolutions 1368 (2001) and 1373 (2001) in holding that these did not support a claim to self-defence by Israel in this case: ‘The Court also notes that Israel exercises control in the Occupied Palestinian Territory and that, as Israel itself states, the threat which it regards as justifying the construction of the wall originates within, and not outside, that territory. The situation is thus different from that contemplated by Security Council Resolutions 1368 (2001) and 1373 (2001), and therefore Israel could not in any event invoke those resolutions in support of its claim to be exercising a right of self-defence. Consequently, the Court concludes that Article 51 has no relevance in this case.’ Thus the Court treated the applicable law as that of occupation. Israel could have no right under Article 51 against terrorist attacks originating in the Palestinian territory occupied by Israel.45 In Armed Activities on the Territory of the Congo (DRC v Uganda)—a case on armed opposition groups conducting cross-border attacks—the Court deliberately and explicitly avoided the controversial issue of self-defence against non-state actors in the absence of state involvement in an armed attack.46

Subsequent Practice

Those who argue that the law has changed or should be changed—that the approach of the ICJ in the Nicaragua case was too restrictive and unreasonable47 (p. 210) and that requirements of the Definition of Aggression as applied in the Nicaragua case should be modified in such a way that self-defence may be invoked against non-state actors operating from a host state which was not complicit in their attacks on the victim state—endeavour to adduce later state practice in support of their argument.48 Writers have invoked military operations in Lebanon, Gaza, Somalia, and Iraq49 (and more recently in Syria),50 but it is not clear that this practice is enough to establish a new wide right of self-defence in the absence of extensive state support for such a doctrine. These writers struggle to explain how the right of self-defence against a non-state actor can justify military action against a host state in violation of its rights under Article 2(4).51 There are also counter-examples in state practice, those of Russia’s intervention in Georgia (2008) and Colombia’s in Ecuador (2008).52

Israel, Syria, and Lebanon 2001–6

The scope of the right to use force against terrorist attacks after 9/11 has predictably proved especially controversial in the Middle East. Israel repeatedly said that it was acting in self-defence against terrorism in its use of force against Lebanon since 9/11, including its regular incursions into Lebanon’s airspace by warplanes and helicopters. It argued that Hezbollah was a terrorist organization, operating from Lebanon, and responsible for a series of attacks on Israeli nationals and armed forces. Israel claimed that Hezbollah has the full support and blessing of Lebanon, Syria and Iran which had persistently refused to meet their obligations to prevent terrorism under Security Council Resolution 1373 (2001). Israel said it had ended its (almost) twenty-year occupation of south Lebanon in June 2000, but Lebanon had not reasserted its governmental authority in the area, as required by Security Council Resolutions 1310 (2000) and 1337 (2001), to prevent cross-border terrorist attacks and ensure effective peace and security. It permitted Hezbollah complete freedom of movement. Syria provided financial, (p. 211) logistical, and political support to Hezbollah; it offered a safe harbour in Syrian-controlled territory and was therefore responsible for Hezbollah’s actions. Israel said that it would adopt the necessary measures to protect its citizens in accordance with the right of self-defence.53

After 9/11 Israel adopted language similar to that of the USA on the war against terrorism; it employed the key concepts of ‘global terrorism’ and ‘harbouring’. Israel claimed that Hezbollah was an organization with extensive terrorist networks around the globe and a lengthy history of global terrorism.54 It accused Syria and Lebanon of ‘harbouring’ Hezbollah. But Israel also argued that Syria and Lebanon actively supported Hezbollah and it was that active involvement which meant that they were responsible for its actions and that Israel was entitled to use force in self-defence against Lebanon and Syrian targets within Lebanon. Israel stressed that Lebanon and Syria were colluding with Hezbollah; that is, it did not expressly claim a right to act against non-state actors in the absence of territorial state involvement.

Lebanon’s position was complex. It was on the strongest ground in objecting to the series of Israeli air force incursions into Lebanon’s airspace and in claiming the right to respond in self-defence. It said that these Israeli acts were acts of aggression and provocation and entitled Lebanon to exercise its right of self-defence, including anti-aircraft fire against Israeli aircraft.55 More controversially, it also argued that Israel remained in illegal occupation of certain Lebanese territory—in the Shab’a farms area—after the withdrawal of its forces in June 2000.56 Therefore the acts of legitimate resistance against the Israeli occupation were not being carried out on Israeli territory, but in occupied territory and against Israeli military positions in that territory. Lebanon refused to condemn Hezbollah as it was acting in response to Israel’s continued illegal occupation of Lebanese territory, in the disputed Shab’a farms area: there was a dividing line between legitimate resistance to occupation in self-defence and terrorism. The actions were not terrorism under Security Council Resolution 1373, but were covered by General Assembly Resolution 46/51 (1991) which distinguished between terrorism and the rights of people to struggle against foreign occupation. If Israeli military aircraft intruded into Lebanon and Hezbollah fired in self-defence, this was part of a legitimate struggle to liberate territory.57

(p. 212) When Israel extended its ‘war on terrorism’ beyond Lebanon and Syrian targets within Lebanon,58 and into Syria itself, on the basis that Syria was harbouring terrorists, there was a strong international rejection of the legality of its use of force. In October 2003, after a Palestinian suicide bomb in a restaurant in Haifa, Israel responded with its deepest raid into Syria since the 1973 war. Israel said that it was acting against a Palestinian terrorist training camp for Islamic Jihad; it warned terrorists not to hide in neighbouring states.59 The UN Secretary-General strongly deplored the Israeli air strike on Syrian territory as well as condemning the preceding terrorist attack.60 The Security Council met at Syria’s request, and Syria accused Israel of aggression and a breach of the 1974 Disengagement Agreement between the two states. Israel claimed that it was acting in self-defence against a state which supported terrorism.61

In the Security Council the majority of states condemned the Israeli action as a violation of international law. Arab states argued that this was a disproportionate armed reprisal and proceeded from a political desire to destroy the peace process and destabilize the region. For Spain, France, and China it was a patent violation of international law. Pakistan accused Israel of exploitation of the campaign against terrorism for other purposes: ‘the answer to individual acts of terrorism is not state terrorism, nor is it wanton attacks against other countries’. Germany said that Israel’s action was ‘unacceptable’ and a violation of the sovereignty of a neighbouring state; the UK said only that the action was unacceptable and did not expressly enter into the question of legality; Russia was also cautious. The USA called for restraint, but it said that Syria was ‘on the wrong side in the war on terrorism’; it was still considered a state sponsor of terrorism and a host to Islamic militant groups. Certain states such as Mexico and Jordan said that the action was clearly a reprisal, not self-defence; in the case of self-defence the right to use force was subject to the commission of an actual military aggression against that state. That is, no general support was expressed for a wide right to use force against terrorist camps in a third state.62

(p. 213) Israel/Lebanon 2006

The 2006 conflict in Lebanon and the international response to it demonstrate a deep doctrinal divide on the scope of self-defence, in particular with regard to proportionality. The central question is whether the ‘war on terror’ gives Israel a wide right to use force.

It is commonly said that the conflict began on 12 July 2006 when Hezbollah launched a cross-border attack on Israeli forces in northern Israel, killed three Israeli soldiers, and abducted two.63 The UN Secretary-General condemned the Hezbollah attacks and called for the release of the Israeli captives.64 The same day Israel wrote to the UN Security Council saying that the attack was a ‘clear declaration of war’ and reserving the right to act in self-defence.65 There was a heavy exchange of fire and Israel mounted increasingly extensive attacks on Lebanon. Its use of force by land, sea, and air continued for a month and involved massive destruction. The UN reported that Israel destroyed roads, airports, bridges, ports, power stations, as well as thousands of houses. The Israeli attacks caused about one thousand civilian Lebanese deaths, injured over 3,500 and displaced almost a million people.66 The air, sea, and land blockade of Lebanon continued after the ceasefire. During the conflict Hezbollah fired hundreds of rockets into Israel, causing fifty civilian casualties and an estimated 114 military deaths, and disrupting the lives of hundreds of thousands of civilians.67

The question arose whether Israel had the right of self-defence against Hezbollah’s attacks, and how far its response was proportionate. Israel’s letter of 12 July 2006 to the Security Council was brief. It reserved the right ‘to act in accordance with Article 51 of the UN Charter and exercise its right of self-defence when an armed (p. 214) attack is launched against a Member of the UN’.68 This is a cautious formulation, based on the universally agreed principle that there is a right of self-defence in response to an actual armed attack. As it turned out, Israel’s use of force went rather beyond this narrow right.

States were divided in their response to the conflict. This may be seen clearly in the Security Council debates.69 Initially, at the first meeting held after the outbreak of the conflict, most members of the Security Council seemed sympathetic to Israel’s claim to self-defence. Only China and Qatar (and, to a lesser extent, Ghana) openly condemned the Israeli actions at this stage. All the European members of the Security Council apart from Russia asserted that Israel had a right to self-defence. The states supporting this right did so in rather general terms which left the scope of the doctrine unclear.70

Many states accepted that the incidents of 12 July 2006 were the start of the conflict. The UN Secretary-General said that ‘Hezbollah’s provocative attack on 12 July was the trigger of this crisis.’71 But others contested this; they said there was no right of self-defence. These incidents were not of sufficient gravity to amount to an armed attack. It was important not to take the minor incident of 12 July out of context; this was one in a series of cross border incidents, and should be seen in the context of the history of the region and Israel’s continued occupation of the Palestinian territories and the Golan Heights.72 The UN Secretary-General’s Report on the UN Interim Force in Lebanon (UNIFIL) of 21 July 2006 listed a long sequence of such cross-border incidents pre-dating 12 July.73 Over the years Hezbollah had fired many rockets from Lebanon over the border into Israel; Israel had conducted what the Secretary-General’s Report called ‘persistent and provocative air incursions’ over Lebanon. But previous incidents had not led to such a massive response by Israel since 1982.74

This conflict raises the question of the degree of state complicity, if any, necessary to justify a forcible response against a state from which non-state actors are operating. Although several states accepted Israel’s right to self-defence in general terms, it is not clear from their statements in the Security Council debates whether they (p. 215) accepted that Israel was entitled to use force against Hezbollah in the absence of complicity of Lebanon. Israel itself was careful to attribute responsibility to Lebanon; in its letter to the Security Council on 12 July it said ‘Responsibility for this belligerent act of war lies with the Government of Lebanon from whose territory these acts have been launched into Israel. Responsibility also lies with the Governments of Iran and Syria, which embrace and support those who carried out this attack.’75

In reply, Lebanon said that it was not responsible for the actions of Hezbollah and accused Israel of an act of aggression.76 At the first Security Council debate on the conflict Lebanon regretted that Israel had held Lebanon responsible for Hezbollah’s acts, even though the Lebanese government had issued a statement on 12 July, declaring that it was not aware of the incident, that it did not take responsibility for it, and did not endorse what had happened.77 Since the departure of the Syrian forces from Lebanon in 2005 following Security Council Resolution 1559 (2004), Lebanon had worked to regain independence with a full commitment to the Council resolutions.78 Israel’s aggression had hampered the efforts exerted towards fostering democracy, since it undermined Lebanon’s sovereignty and attempts to exercise its authority over its entire territory.79

The UN Security Council played a very limited role in the conflict; it was effectively side-lined in what the USA, the UK, and Israel portrayed as part of the ‘war on terror’. The USA and the UK indicated that they would not accept a call for an immediate ceasefire by the Security Council, even though Lebanon had called for a ceasefire from the start of the conflict, and even though the UN Secretary-General had subsequently supported this call, saying that the authority and standing of the Security Council were at stake if it did not play a role in securing an end to the conflict.80 The Non-Aligned Movement81 and ASEAN (p. 216) also called for a ceasefire.82 However, the USA and the UK said that it was necessary to secure a ‘durable and sustainable cease-fire’: the violence would end only when Hezbollah had been disarmed or removed from the border. The UK and the USA were not willing to allow the Security Council to call for an immediate end to the fighting.83 This was taken as a green light by Israel to continue its military campaign. In its first resolution after the outbreak of the conflict the Security Council merely expressed deepest concern at the escalation of hostilities since 12 July 2006.84 It was not until 11 August that it called for a ‘full cessation of hostilities’ in Resolution 1701 (2006). The Secretary-General indicated his regret that the Security Council had not called for the immediate cessation of hostilities earlier.85

Gaza (2008–9, 2012, 2014)

The series of conflicts in Gaza—including Operation Cast Lead (2008–9), Operation Pillar of Defence (2012), and Operation Protective Edge (2014)—gave rise to similar questions. First, and most fundamentally, was Israel entitled to rely on a right of self-defence under Article 51 against rocket attacks by Hamas86 and Islamic Jihad from Gaza, or was a different set of rules derived from the law of occupation applicable? If Gaza remained occupied territory despite Israel’s withdrawal of its troops in September 2005 then, according to the ICJ in the Wall Opinion, Israel would not be able to invoke Article 51. Israel insists that it is no longer an occupying power,87 but UN bodies reject this claim because Israel continues to control Gaza’s borders, territorial waters, and airspace, its electricity, water, and telecommunications.88 Israel has also imposed a blockade on Gaza since 2007 when Hamas seized power; Israel then declared Gaza a ‘hostile entity’.89 It did not explain the legal significance it attached to this term with (p. 217) regard to the law on the use of force.90 The language of Israel in its letters to the Security Council changed significantly over time. In the 2008–9 conflict it referred to Article 51 to justify its use of force.91 In contrast it did not do so in the 2012 and 2014 conflicts.

In Operation Cast Lead (2008–9) Israel said it was acting to protect its civilians from the ongoing terrorist attacks from the Gaza strip carried out by Hamas and other terrorist organizations.92 Its decisive response was in accordance with ‘the inherent right of every State to self-defence as enshrined in Article 51’. It claimed that its actions were targeted solely at the terrorists and their infrastructure. The operation continued for twenty-two days against the heavily populated territory of Gaza.93 In 2012 Israel did not expressly invoke Article 51 to justify its eight-day Operation Pillar of Defence.94 It again said that it was acting to protect its citizens from Hamas terror. In Operation Protective Edge (2014), the third and deadliest conflict that lasted for fifty days and caused massive destruction,95 Israel said that it was acting to remove the threat posed by Hamas by destroying its military infrastructure, including its rockets and its network of tunnels under the border into Israel. It was not looking for a ‘band-aid solution’ that would allow Hamas to rest and recoup.96 Again it did not write to the Security Council to report its actions under Article 51,97 and it did not refer to Article 51 in the debates.98

As for the international response to these conflicts, there was very general condemnation of the firing of rockets by Hamas into Israel. But those states sympathetic to Israel in 2008–9 spoke of self-defence in general terms without reference to Article 51.99 Other states rejected any claim to self-defence by Israel. Thus (p. 218) the Non-Aligned Movement in 2009 strongly condemned ‘the massive military aggression’.100 The Arab League said that the conflict in Gaza was not part of the war on terror; Israel was the occupying power and it was using self-defence as a pretext.101 There was no public Security Council debate on the 2012 conflict. In 2014 many states that joined in the series of Security Council debates accepted Israel’s right to defend or protect itself or its citizens, or acknowledged its security concerns, but none made any reference to Article 51.102 Other states rejected any claim to self-defence; they condemned Israel as the aggressor, said that its military operation amounted to collective punishment, and called for an end to the occupation and the blockade.103

Other conflicts

In other conflicts the state using force against non-state actors did not unequivocally invoke self-defence against non-state actors in a third state. The significance of this practice is therefore doubtful.

Ethiopia/Somalia 2006

The 2006 conflict in Somalia raises interesting questions about self-defence, but the failure of the states involved adequately to explain their actions in legal terms and the reluctance of other states to enter into legal debate in the Security Council or elsewhere makes assessment difficult. For many years after the overthrow of President Siad Barre and the outbreak of civil war in 1991 Somalia was without an effective government. The UN intervention from 1993 to 1995 did not re-establish peace and security; the US-led Unified Task Force (UNITAF) failed to carry out its mandate of disarming the warlords.104 The UN force withdrew in March 1995. The arms embargo imposed by Security Council Resolution 733 (1992) remained in force. The Secretary-General reported that during the years without a functioning government the country suffered tremendous destruction and neglect. In addition to the physical damage, the foundations and institutions of the society had been almost completely destroyed.105

In 2004 agreement was reached between the competing groups on the establishment of a Transitional Federal Government (TFG) backed by Ethiopia.106 This government was given express AU and Security Council support.107 However, (p. 219) the TFG did not exercise control over the territory.108 It faced a serious challenge from the Union of Islamic Courts (UIC) which had been established in Somalia in 1999. Ethiopia and the USA accused the Union of Islamic Courts of being a terrorist organization with strong links to Al Qaida and with plans to create a greater Somalia incorporating parts of Ethiopia and Kenya. Others regarded it as a more disparate coalition of moderates and extremists.109

The continuing instability was fuelled by increasing arms flows into Somalia in violation of the arms embargo. These were repeatedly condemned by the Security Council.110 A series of UN reports set out the details of foreign intervention: the main assistance to the TFG came from Ethiopia and to the Union of Islamic Courts from Eritrea.111 The UN reports expressed concern that the regional rivalry between the two states manifested in the 1998–2000 conflict between them was being played out in Somalia.

In June 2006 the Union of Islamic Courts seized the capital, Mogadishu. It brought about an overall improvement in security and reopened the international airport and the main seaport which had been out of operation for more than a decade.112 A ceasefire was then agreed—the Khartoum declaration—but the two sides subsequently accused each other of violating its provisions.113 On 6 December the Security Council called for the resumption of peace talks. Resolution 1725 (2006), passed unanimously under Chapter VII of the UN Charter, clearly supported the TFG against the Union of Islamic Courts. In the preamble it called upon the Union of Islamic Courts to cease any further military expansion and to reject those with an extremist agenda or links to international terrorism. In the operative part of the resolution the Security Council reiterated that the TFG offered the only route to achieving peace and stability in Somalia and emphasized the need for dialogue. It authorized the establishment of a regional mission in Somalia, modified the arms embargo accordingly, and specified that those states that border Somalia should not deploy troops.114

(p. 220) But the Security Council’s call for dialogue proved ineffective. The TFG welcomed the resolution, but the Union of Islamic Courts rejected it, saying that the deployment of foreign troops in Somalia would be tantamount to an invasion.115 The Union of Islamic Courts called for the withdrawal of Ethiopian troops; when they did not leave it launched a major offensive.116 At first Ethiopia denied that it had sent troops; then on 24 December 2006 it admitted that it had done so and claimed that it had acted in self-defence. It sent tanks and helicopters to assist the TFG and its ground troops penetrated deep into Somalia. It also carried out air attacks on the main airports to prevent the Union of Islamic Courts from bringing in military supplies.117

It is interesting that Ethiopia did not report this action to the Security Council under Article 51 of the UN Charter, especially as it had so reported in its earlier conflict with Eritrea.118 However, the Prime Minister of Ethiopia said in an official statement that it had ‘taken self-defensive measures and started counter-attacking the aggressive extremist forces of the Islamic Courts and foreign terrorist groups’.119 In a letter to a British newspaper the Ethiopian Ambassador said that Ethiopia went into Somalia for reasons of self-defence. The Union of Islamic Courts had declared a jihad against Ethiopia; twenty terrorist actions had been taken against Ethiopia by the leaders of the Union of Islamic Courts.120 On 2 January 2007 the Prime Minister of Ethiopia in a speech to parliament set out the justification for the use of force at greater length. Attempts to negotiate a peaceful settlement had failed; the extremist leadership of the Union of Islamic Courts had completed its preparation to launch an all-out war against the TFG. Ethiopia accordingly had prepared a plan for counter-offensive to protect the country from attack and had implemented the plan in coordination with the TFG. The Prime Minister claimed the unequivocal and public support of the African Union.121 He said that only one state had challenged the self-defence measure of Ethiopia. ‘Therefore the UN Security Council did not put into question the measures we took in self-defense. Similarly various governments in different parts of the world have supported our right to self-defense and have refrained from putting out any kinds of declarations which might have put into question our inherent right of self-defense.’ He said that the only party which took a different position on the issue was the creator of the problem, the government of Eritrea. Although the main aim of Ethiopia was to protect itself from attacks, it also supported the (p. 221) efforts of the people of Somalia to disengage themselves from the Taliban-like rule of extremists. Upon completion of the final phase of the mission Ethiopia would withdraw its forces as soon as possible.122 Both the USA and Ethiopia portrayed the conflict as part of the ‘war on terror’. They claimed that the Union of Islamic Courts was controlled by Al Qaida members.123 The USA tacitly supported the Ethiopian action.124 There were newspaper reports that the USA had provided practical help and that it was conducting a counter-terrorism operation against Al Qaida by proxy through Ethiopia.125

By early January 2007 the Ethiopian army and the TFG had driven Union of Islamic Courts forces out of Mogadishu and the regions they controlled. The Union of Islamic Courts abandoned the battle.126 The AU Peace and Security Council issued an optimistic communiqué on 19 January 2006 proclaiming that there was ‘Today a unique and unprecedented opportunity to restore structures of government in Somalia and to bring about lasting peace and reconciliation.’ It authorized deployment of a regional peacekeeping force, AU Mission in Somalia (AMISOM).127 However, the UN Secretary-General reported at the end of February that the ‘semblance of law and order that the UIC had created in Mogadishu’ had begun to deteriorate. Insecurity had increased. The TFG was not able to establish effective authority. There were repeated attacks on Ethiopian forces. Public resentment of the continued presence of Ethiopian troops in Somalia had created a volatile situation.128

There is some uncertainty as to the precise legal basis for the Ethiopian action.129 Ethiopia generally denied the presence of its forces in Somalia until December 2006. It then claimed self-defence. This was clearly not self-defence against an armed attack by government forces, but apparently self-defence as part of the ‘war on terror’ against the threat posed by the Union of Islamic Courts, and against its past terrorist attacks. There was no report to the Security Council under Article (p. 222) 51. Ethiopia did not offer any reasoned legal case in defence of its use of force in the UN. Its major military operations extending far beyond the border area look more like action to protect the TFG government against the Union of Islamic Courts than self-defence of Ethiopia.130 A stronger legal basis for intervention might have been intervention at the invitation of the legitimate (though ineffective) government supported by the UN, in response to prior foreign intervention as set out in the UN reports. The Prime Minister of the TFG after the event spoke of ‘Ethiopia’s intervention on behalf of the UN-backed TFG’.131 There were indications in the speech of the Prime Minister to the Ethiopian parliament on 2 January 2007 that this was an additional basis for its use of force, but it was not entirely clear how far this was being put forward as a legal argument.

There was very little international discussion of the legality of the conflict. At the start of the conflict the Security Council issued a Presidential Statement expressing deep concern and calling on all parties to draw back from conflict.132 The Security Council met several times to discuss the conflict but there is no record of its discussions. On 20 February it unanimously passed Resolution 1744 (2007) authorizing AU member states to set up a regional force, AMISOM, in Somalia. Again there was no discussion of the legality of the use of force. In its preamble Resolution 1744 welcomed the decision of Ethiopia to withdraw its troops from Somalia, and took note that it had already started the withdrawal. It underlined that the deployment of AMISOM would help avoid a security vacuum and create the conditions for a full withdrawal.133 Thus there was no public Security Council debate on the Ethiopian use of force, there was no call by the Security Council for an end to the fighting, and no determination of the legality of the Ethiopian action.134

The AU seemed sympathetic to Ethiopia. The AU Assembly—held in Ethiopia in January 2007—issued a decision in which it ‘noted with satisfaction the recent positive developments in Somalia which have resulted from Ethiopia’s intervention upon the invitation of the legitimate TFG of Somalia, and which has created unprecedented opportunity for lasting peace in the country’. It later welcomed the decision of Ethiopia to withdraw its troops from Somalia.135 Ethiopia claimed to have done so in (p. 223) 2009.136 But AMISOM remained, and it faced serious challenges from AlShabaab which began to emerge as the successor to the Union of Islamic Courts in 2006, and declared its affiliation to Al Qaida in 2012.137 When Ethiopian troops were formally integrated into AMISOM in January 2014,138 there was concern that the Ethiopian presence would once again incite attacks by those who resented its intervention in Somalia.139

Kenya has also taken military action in Somalia—against AlShabaab. It staged a major land and air incursion in 2011 in response to AlShabaab kidnappings in Kenya.140 Kenyan troops then remained in Somalia, technically as part of AMISOM.141 Once again there was some uncertainty as to the legal basis for its 2011 action. Kenya did not report this to the Security Council under Article 51; it did later refer to Article 51 in a joint communiqué it issued with the TFG after the 2011 action.142 However, this communiqué also made it clear that Kenya was acting with the consent of the government of Somalia.143

Turkey v PKK in Iraq (2015 onwards)

We have seen in the previous chapter that Turkey did not officially invoke self-defence to justify its air and ground incursions into Iraq against the PKK before the 2013 ceasefire.144 It did not report its actions to the UN Security Council under Article 51. Nor did it do so in relation to its more recent attacks on the PKK in Iraq after the breakdown of the ceasefire in July 2015. This was in marked contrast to Turkey’s justification of its attacks on ISIS in Syria: Turkey did write to the Security Council under Article 51 to report its right to individual and collective self-defence against ISIS in Syria.145 And when it carried out a simultaneous (p. 224) operation against the PKK in Iraq and ISIS in Syria it did again report this to the Security Council.146 There was at first a widespread suspicion that Turkey was in fact more interested in taking action against Kurdish groups—the PKK in Iraq and the YPG in Syria147—than in joining coalition operations against ISIS, and Turkey did carry out major air strikes on the PKK in Iraq in 2015–17.148 Iraq has repeatedly protested about these violations of its sovereignty.149

Turkey also claimed that it had the right to maintain bases in northern Iraq and to send in ground troops to reinforce the bases, even after Iraq denied that it consented to the presence of the bases and called on Turkey to withdraw its forces. Iraq took this question to the Security Council, and called on the Council to take steps to throw the Turkish forces out of Iraq.150 It said: ‘Iraq rejects, strenuously opposes and condemns in the strongest possible terms any military movements aimed at countering terrorism that take place without prior consultation with the federal Government of Iraq and without its approval.’151 However, there was almost no discussion. Turkey’s justification was not entirely clear: it did not write to the Security Council under Article 51, but in the Security Council it claimed self-defence to defend its bases in Iraq against a terrorist organization.152 Its underlying concern in maintaining these bases was apparently to ensure that only forces acceptable to it would take part in the liberation of Mosul (in Iraq) from ISIS. It expressed concern over the future of the ethnic Turkmens in Mosul.153 The Arab League condemned Turkey’s actions as a violation of Iraqi sovereignty.154 The Secretary-General urged Iraq and Turkey ‘to accelerate their bilateral efforts to find a mutually acceptable solution regarding the presence of Turkish troops in northern Iraq that will fully respect the principles of sovereignty, territorial integrity and non-interference in the internal affairs of Iraq and ensure that all activities conducted in Iraq are done so in coordination with and with the full agreement of the Government of Iraq’.155 However, the Turkish (p. 225) troops remained in May 2017 and Iraq once again called on the Security Council to ensure that Turkey withdraws its military forces from Iraq immediately.156

Colombia/Ecuador (2008)

This minor episode has been included by some writers in their list of state practice allegedly supporting a wide right of self-defence against non-state actors, but it cannot be interpreted in this way.157 In 2008 Colombian forces crossed into Ecuador to attack Revolutionary Armed Forces of Colombia (FARC) guerillas who had been involved in armed conflict against the government of Colombia for over forty years. However, Colombia did not report its action as self-defence under Article 51. It also accused Ecuador of support for the FARC. Ecuador protested to the Security Council.158 In this case the OAS condemned the incursion. It ‘reaffirmed the principle that the territory of a state is inviolable and may not be the object even temporarily of military occupation or other members of force taken by another state, directly or indirectly, on any grounds whatsoever’.159 Colombia apologized for its actions.160 This incident demonstrates that the OAS maintained its traditional stance against forcible intervention, and that it was not willing to accept a wide right of self-defence against non-state actors.

Russia and Georgia (2002)

The USA was reluctant to accept any right of Russia to use force in self-defence against non-state actors with regard to the situation in Georgia where Chechen forces operated in the Pankrisi Gorge area.161 Russia bombarded Chechen positions in Georgia several times in response to terrorist attacks by Chechens in Russia. In a letter to the Security Council on the first anniversary of 9/11 it used the language of self-defence:

The Chechen Republic, where international terrorist organizations, including the not unknown Al Qaida, have expanded their activities on a full-scale basis, has for a long time remained a source of extremism and terrorism in our country’s territory. The continued existence in separate parts of the world of territorial enclaves outside the control of national governments, which, owing to the most diverse circumstances, are unable or unwilling to counteract the terrorist threat is one of the reasons that complicate efforts to combat terrorism effectively. The Pankisi Gorge is one such place. From 1999 Russia has attempted to arrange cooperation with Georgia on issues relating to combatting terrorism. If the Georgian leadership is unable to establish a security zone in the area of the border, continues to ignore (p. 226) Security Council Resolution 1373 and does not put an end to the bandit sorties and attacks on adjoining areas of Russia, we reserve the right to act in accordance with Article 51 of the UN Charter.162

The USA in response stressed the rights of Georgia. It seemed not to accept the Russian claims; it deplored the violations of Georgian sovereignty and spoke of bombings by Russian aircraft ‘under the guise of antiterrorist operations’, even though it acknowledged that Georgia had not been able to establish effective control over the eastern part of the country and accepted a link between the Chechen forces and Al Qaida.163 The USA itself provided training and other assistance to help the Georgian authorities to implement tighter anti-terrorism controls and so did the UK.164 This reluctance by the USA to acknowledge the right of another state to invoke self-defence against terrorism, even in a neighbouring state, and even where it may legitimately claim to have a strong case, seems to make it more difficult to claim that the events of 9/11 and the response have established a new customary rule. In this episode we see the USA denying to others wide rights of self-defence that it claims for itself and its allies.

Summary of practice

Many writers have claimed that this practice establishes a clear right to use force in self-defence against non-state actors, even in host states that were not complicit in the terrorist attacks on the victim state. But this practice is limited and unclear. The writers who support a wide right of self-defence struggle to reconcile this with the rights of the host state to territorial sovereignty and the prohibition of the use of force under Article 2(4).165 Some argue for a wide doctrine of attribution of an armed attack by a non-state actor to a state (going beyond the Nicaragua test derived from the Definition of Aggression), a wide doctrine that would allows self-defence against a state in response to a terrorist attack by non-state actors on the basis that even if the state was not substantially involved in the sending of the armed group, it had some other form of substantial involvement with the non-state actor (along the lines suggested by the dissenting judges in the (p. 227) Nicaragua case).166 Others argue that if a host state is in breach of its duty of due diligence and does not take effective action against the non-state actors on its territory, this means that it loses its rights under Article 2(4).167 Some also argue that this practice shows the emergence of an ‘unwilling or unable’ doctrine—that the test for when it is legal to use force against non-state actors in a third state is whether that state is unwilling or unable to prevent attacks from its territory.168 These problematic claims on the scope of self-defence will be discussed below with reference to targeted killing and to the conflicts in Iraq and Syria.

Necessity and Proportionality

Another problem arising out of any right of self-defence against past terrorist actions is the application of the requirement that self-defence be necessary and proportionate. If force is used in response to past attacks, it may not be necessary self-defence as the harm has already been done. Insofar as self-defence against terrorism is designed to deter and prevent future terrorist acts it is difficult, if not impossible, to employ these central criteria of self-defence in the absence of detailed evidence about a specific threatened attack. If these future threats are portrayed as existential then proportionality does not operate to limit the use of force.169 The USA and the UK, which both support a wide right of self-defence against imminent attacks, claim that they may take measures proportionate to the threat of a future attack, rather than merely to a specific armed attack which is underway or which has already taken place.170 Israel also took a wide approach to necessity and proportionality in its conflicts in Lebanon and Gaza.

Israel in Lebanon and Gaza

Israel’s massive use of force in Lebanon in 2006 was clearly not proportionate if seen as a response to the events of 12 July 2006 or to past attacks by Hezbollah, even if those attacks could be taken cumulatively. Israel claimed that its acts were aimed at Hezbollah, not at Lebanon; they were targeted at Hezbollah strongholds and infrastructure, not at civilian targets.171 Lebanon strongly rejected this (p. 228) argument; it said ‘from the start it had been clear that it was not Hezbollah that was the target, but Lebanon. Its infrastructure was the target and hundreds of civilians had been killed before Israel had even taken up any campaign against Hezbollah and its positions.’172

Most states condemned Israel’s use of force as disproportionate.173 A few members of the Security Council were not willing to do this; they merely called on Israel to ensure that its acts were not disproportionate.174 But many others such as France and Argentina which had initially asserted that Israel had a right to self-defence subsequently condemned its actions. India, Brazil, Chile, Djibouti, Switzerland, and New Zealand, as well as many Arab states, all condemned the excessive use of force.175

However, Israel, the USA and the UK demonstrated a different understanding of proportionality in this case. Israel said in its letter to the Security Council: ‘These acts pose a grave threat not just to Israel’s northern border, but also to the region and the entire world.’ It argued that the conflict should be seen as part of the ‘war on terror’.176 ‘In this vacuum [of southern Lebanon] festers the Axis of Terror: Hezbollah and the terrorist states of Iran and Syria, which have today opened another chapter in their war of terror.’177 Israel argued that the aim of Hezbollah, supported by Iran, was to destroy Israel and that therefore Israel’s use of force was proportionate to the threat posed by Hezbollah.

The Prime Minister of Israel had ‘made clear that Israel had decided that military operations would continue until Hezbollah was seriously weakened; this was not, as in the past, a response to a particular incident but was a definitive response to an unacceptable strategic threat posed by Hezbollah and a message to Iran and Syria that threats by proxies would no longer be tolerated’.178 The actions of Israel were pre-emptive insofar as they were designed to stop future attacks by Hezbollah. Hezbollah was portrayed as a threat to the existence of Israel. But, however intolerable its rocket attacks on the civilians of Israel, this is not a convincing picture, given the vast disparity of resources. As Ghana said, ‘The reality of Israel’s absolute military dominance in the region belies the oft-repeated claim that this powerful country must take extreme measures to protect itself, even if that means laying waste to another sovereign state that is obviously very weak.’179

(p. 229) The USA and the UK refused to condemn Israel’s actions as disproportionate, or to allow a call for an immediate ceasefire by the Security Council.180 They used the ongoing ‘war on terror’ as justification for their support for Israel’s campaign to wipe out Hezbollah. After the Security Council’s adoption of the ceasefire resolution, President Bush said that responsibility for the suffering lay with Hezbollah. ‘It was an unprovoked attack by Hezbollah on Israel that started this conflict. Responsibility for the suffering of the Lebanese people also rests with Hezbollah’s states sponsors, Iran and Syria. The regime in Iran provides Hezbollah with financial support, weapons and training. Iran has made clear that it seeks the destruction of Israel. We can only imagine how much more dangerous this conflict would be if Iran had the nuclear weapon it seeks. Syria is another state sponsor of Hezbollah. Syria allows Iranian weapons to pass through its territory into Lebanon. Syria permits Hezbollah’s leaders to operate out of Damascus and gives political support to Hezbollah’s cause. Syria supports Hezbollah because it wants to undermine Lebanon’s democratic government and regain its position of dominance in the country.’181 This view was not convincing to a majority of states; the 118-member Non-Aligned Movement condemned the Israeli use of force against Lebanon as aggression.182

A ceasefire was finally agreed under Resolution 1701(2006), passed unanimously, but the resolution perpetuated the dispute about the scope of self-defence. The resolution seemed weighted in favour of Israel in that it called for ‘a full cessation of hostilities based upon, in particular, the immediate cessation by Hezbollah of all attacks and the immediate cessation by Israel of all offensive military operations’. This left open the prospect that Israel would take a wide view of defensive action, to include further pre-emptive actions against Hezbollah.183 Some states expressed reservations about this language during the negotiations and at the time of adoption.184 Although the government of Lebanon, working with the UN force UNIFIL, did extend its control over almost the whole of southern Lebanon, the situation in Lebanon remained unstable, with occasional clashes between Israel and Hezbollah.185 Since 2011 the Syrian conflict has threatened a (p. 230) dangerously destabilizing effect on Lebanon which hosts over one million Syrian refugees.186

The series of conflicts in Gaza also raise issues of necessity and proportionality. Although Israel paints a dramatic picture of the threat posed by indiscriminate rocket attacks from Gaza, and gives a harrowing account of their impact on the civilians affected, there is no existential threat to Israel. Israeli casualties remain very low. It is also clear after many years of conflict that there is no military solution to the problem, as many states pointed out in the Security Council meetings on Gaza. There is a vicious cycle of attack and counter-attack with each side blaming the other for initiating the conflicts.187 The vast majority of states condemn the rockets fired from Gaza. But it is difficult to argue that Israel’s major military campaigns are necessary, given that they have proved ineffective. It is also difficult to argue that no alternative response is possible. If a solution is to be found, the underlying problems of the occupation of Gaza and the West Bank since 1967, the blockade of Gaza since 2007, and the implementation of the right of self-determination of the Palestinian people must be resolved.188

As regards proportionality, in purely numerical terms, there is an striking contrast between the very small numbers of Israeli casualties and the much larger numbers of Palestinians killed. This is especially true of the 2008–9 and 2014 conflicts.189 The scale of destruction in Gaza caused by air, sea and ground attacks on the densely populated area was massive. This led the vast majority of states speaking in the open meetings of the Security Council to condemn Israel’s response to the rocket attacks as disproportionate.190 However, in none of the conflicts was (p. 231) there a prompt Security Council resolution calling for a ceasefire. For example, in 2008–9 the USA first delayed a resolution and then abstained on Resolution 1860 (2009) which called for an immediate ceasefire. Israel expressly rejected the call for a ceasefire until 17 January 2009.191 In 2012 the Security Council could not agree on a response to the eight-day conflict, and again in 2014 there was no Security Council resolution calling for a ceasefire in the fifty-day conflict.

Operation Enduring Freedom

Operation Enduring Freedom continued in Afghanistan for over thirteen years from its inception. It can be asked how far Operation Enduring Freedom was necessary and proportionate, because the operation continued for such a long time. It began in October 2001 with an air campaign against fixed targets such as air defence, communication centres and command and control centres, air bases, and training camps. It then went on to target the positions of Taliban and Al Qaida forces. At first, the US military campaign operated in cooperation with the Northern Alliance, Afghan opposition forces which had been fighting the Taliban regime in Afghanistan for many years. Together they forced the Taliban to evacuate Kabul in November 2001 and drove them from power. The defeat of the Taliban weakened Al Qaida’s support base in Afghanistan.192 At the end of 2002 Afghanistan concluded a non-aggression pact with its neighbours, China, Pakistan, Iran, Turkmenistan, Uzbekistan, and Tajikistan. This was intended to end foreign interference in Afghanistan, something which had contributed to the continuation of twenty years of conflict after the USSR withdrew its troops in 1989; the pact was welcomed by the Security Council in Resolution 1453 (2002).193 However, the USA repeatedly expressed concern that Al Qaida terrorists had fled into Pakistan and were operating from there and it put pressure on Pakistan’s government to act more strongly against them.194

The political settlement in the Bonn Agreement in December 2001 and the establishment of a UN-authorized International Security Assistance Force (ISAF),195 in January 2002, to assist the government of Afghanistan in the maintenance of (p. 232) security, did not bring peace or stability to Afghanistan. Military operations by Operation Enduring Freedom continued in pursuit of Al Qaida and Taliban forces. The pronouncement by US Defense Secretary Rumsfeld in May 2003 that major combat operations were over proved distinctly premature.196 Operation Enduring Freedom finally came to an end in December 2014, but the USA replaced it with Operation Freedom’s Sentinel.197 The situation in Afghanistan is still unstable in 2017. The Taliban is resurgent. At the end of 2016 the Secretary-General reported that ‘The security situation further deteriorated during the reporting period with intensifying armed clashes between the Afghan security forces and the Taliban.’ Overall the number of armed clashes surpassed the previous record year of 2011.198 The Security Council has expressed its concern at the continuing violence and terrorist attacks by Al Qaida and the Taliban in a long series of resolutions.199

The USA involved other states—initially Australia, Poland, and the UK—directly in Operation Enduring Freedom in what may be seen as a quest for political legitimacy, even though it was not willing to accept the constraints of acting through NATO or the UN. Many other states participated in Operation Enduring Freedom in a support capacity.200 The USA could thus argue that its action was not unilateral but that of a ‘Coalition against Terror’. This search for legitimacy through wider international participation became increasingly important as Operation Enduring Freedom continued, with no express UN basis beyond the initial reference to self-defence in Security Council Resolutions 1368 (2001) and 1373 (2001). The longer Operation Enduring Freedom continued, the further it was detached from its initial basis in self-defence. It may be that awareness of this led to express reference to Operation Enduring Freedom in a series of Security Council resolutions; the first reference was in Resolution 1510 (2003) which called upon ISAF to continue to work in close consultation with the Operation Enduring Freedom coalition in the implementation of its mandate.201 These resolutions may be seen as implicit acceptance of the legality of Operation Enduring Freedom by the Security Council, but they contain nothing express on its legal basis, and there was no discussion of this in the Security Council.

Initially, perhaps this military campaign in Afghanistan could be seen as a new war against an unprecedented act of terrorism. For many years the USA maintained (p. 233) that the conflict was the front line in the war on terror.202 But it can be argued that the conflict in Afghanistan demonstrates that the ‘war on terror’ is self-perpetuating and cannot be won by military means.203 In its prolonged support for an Afghan government unable to retain power on its own against fundamentalist Islamist and ethnic opposition forces, Operation Enduring Freedom came to seem somewhat reminiscent of the earlier Soviet occupation of Afghanistan from 1979–89. The successor operation—Operation Freedom’s Sentinel—is today present in Afghanistan under an agreement with the government,204 and its role still includes counter-terrorism operations in defence of Afghanistan and the USA.205 There are more fundamental questions as to how far the use of force is an effective response to terrorism. It is not clear that the forcible response to 9/11 has in fact deterred future terrorist attacks: if it is not an effective response, then it may be argued that it cannot be a necessary response.206

Targeted Killing

The USA not only asserts a continuing right to self-defence in response to the terrorist attacks of 9/11 inside Afghanistan, it also claims that its right to self-defence covers targeted killings207 of suspected members of Al Qaida and its affiliates outside Afghanistan.208 President Obama rejected the language of a ‘global (p. 234) war on terror’ in 2008, but he maintained that the USA was still at war with Al Qaida and its terrorist affiliates that supported continuing efforts to attack the USA, its allies and partners.209 As part of this ongoing war, he vastly increased the use of drones for targeted killing of members of Al Qaida in Pakistan, AQAP in Yemen, and AlShabaab in Somalia.210 President Trump has continued this programme. It seems that this policy was adopted in reaction to the unhappy, and arguably unproductive, experience of prolonged US occupation of Afghanistan and Iraq. Targeted killing was seen as preferable to ‘boots on the ground’. The USA attempted to set out a legal framework to justify this controversial practice in a series of speeches by members of the Obama administration.211 It was in this context of targeted killing that the USA expanded its wide doctrine of self-defence against non-state actors in third states that had not themselves been involved in the 9/11 or subsequent terrorist attacks.

Because the USA claims that it has been involved in an ongoing armed conflict with Al Qaida and its affiliates since 2001,212 it does not see any need to justify each individual targeted killing as necessary and proportionate self-defence.213 This US position is very controversial. Many do not accept the existence of such (p. 235) an ongoing armed conflict outside Afghanistan against a diverse range of terrorist groups, some of which took no part in the 9/11 attacks.214 Nor do they accept a continuing right of self-defence in response to 9/11. The US case is that the armed conflict and the right to self-defence continue because there is a ‘continuing imminent threat’ from Al Qaida and its affiliates; it describes this threat in broad terms—as a threat to the USA, its nationals, its allies, and its interests. The USA takes a wide and creative approach to the question which groups count as affiliates or associates of Al Qaida for this purpose.215 But the lack of transparency about the targeting process makes it very difficult, if not impossible, to assess whether a particular individual or group of people did indeed pose a continuing threat to the USA.216 This problem arises even when the USA relies on the consent of the host state (as in Yemen and Somalia, and now Libya) to justify its targeted killings on the territory of a third state that was not complicit in the terrorist attacks.217

As a crucial part of its claim to self-defence, the USA has developed a very wide interpretation of imminence.218 It asserts that the assessment of imminence could include ‘considerations of the window of opportunity to act, the possible harm that missing the window would cause to civilians, and the likelihood of heading off future disastrous attacks against the USA’.219 In 2016 US State Department Legal Adviser Brian Egan returned to this issue in a speech on the ‘counter-ISIL (p. 236) campaign’.220 He said that when considering whether an armed attack is imminent the US considers a number of factors: ‘the nature and immediacy of the threat; the probability of an attack; whether an anticipated attack is part of a concerted pattern of continuing armed activity; the likely scale of the attack and the injury, loss or damage likely to result therefrom in the absence of mitigating action; and the likelihood that there will be other opportunities to undertake effective action in self-defense that may be expected to cause less serious collateral injury, loss or damage. The absence of specific evidence of where an attack will take place or of the precise nature of an attack does not preclude a conclusion that an armed attack is imminent for purposes of the exercise of the right of self-defense, provided that there is a reasonable and objective basis for concluding that an armed attack is imminent.’ This US doctrine seems far removed from any normal understanding of imminence in that it does not require any imminence in time. It offers an extremely wide discretion to the state using force.221 It does not make clear the relative importance of the different factors or how they are to be weighed against each other. It is also open to the objection that this right of self-defence is essentially preventive. Such an approach was rejected by the ICJ in DRC v Uganda. Nevertheless, the UK has recently joined the USA in adopting this doctrine of imminence, and there are ongoing talks between those states, Australia, Canada, and New Zealand on this question.222

Another controversial aspect of the US legal argument on targeted killing is its reliance on the ‘unwilling or unable’ doctrine. The USA claims a right to self-defence against imminent attacks (or imminent threats) by non-state actors in states that are unwilling or unable to take effective action against terrorists. Members of the Obama administration mentioned this only briefly in their speeches on targeted killing, and its content was not fully worked out. For example, National Security Adviser (and later CIA Director) John Brennan said: ‘We reserve the right to take unilateral action if or when other governments are unwilling or unable to take the necessary actions themselves.’223 In his 2016 speech Brian Egan expanded on this in an attempt to clarify the nature of the doctrine. He said that the USA regarded the ‘unwilling or unable’ doctrine as part of the requirement that self-defence be (p. 237) necessary. This approach was formally adopted in the 2016 White House Report on Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations.

This legal framework for self-defence was originally developed by the USA with regard to the targeted killing of individual or groups of alleged terrorists in Pakistan, Yemen, and Somalia; it has subsequently been applied to the rather different situation of the US-led intervention against ISIS in Syria.


In the case of Syria the USA set out its wide doctrine of self-defence in a new context, that of operations against a terrorist organization that had seized control of large parts of Iraqi and Syrian territory. US State Department Legal Adviser Brian Egan’s exposition of the US position on counter-terrorism was followed by a 2016 White House Report on Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations. The USA gained some support for its position that it was lawful to use force in self-defence against non-state actors in a state that had not taken part in their attacks on Iraq, but few states expressly relied on the ‘unwilling or unable’ doctrine. Some states said that the military operations in Syria were an exceptional case because of the unique threat posed by ISIS. Syria rejected the US claims to a wide right of self-defence against ISIS as fundamentally inconsistent with the Charter framework, given the prohibition of the use of force in Article 2(4).

In September 2014 Iraq wrote to the Security Council inviting assistance against ISIS. It did not mention Article 51; it did not use the language of armed attack. It said that ISIS had established a safe haven ‘outside Iraq’s borders’ that was a direct threat to Iraq’s security. ISIS had secured for itself the ability to carry out terrorist operations across the border.224 Iraq did not accuse Syria of involvement in the terrorist operations. The USA responded by asserting a right to individual and collective self-defence ‘as reflected in Article 51 of the Charter of the United Nations, when, as is the case here, the government of the State where the threat is located is unwilling or unable to prevent the use of its territory for such attacks.’225 It said that there was a serious threat of continuing attacks from ISIS coming out of safe havens in Syria. That is, the USA claimed a right to act in collective self-defence of Iraq, and also in individual self-defence to address the terrorist threats from ‘Al Qaida elements’ in Syria.226 This was its first invocation of the ‘unwilling (p. 238) or unable’ doctrine in a letter to the Security Council. Similar language was later used by some of the other states taking part in the US-led coalition.

The USA began Operation Inherent Resolve against ISIS in Iraq and later extended this to Syria. The US-led coalition carried out over 10,000 air strikes in Iraq and over 6,000 in Syria by the end of 2016. At the initial stage several states drew a distinction between intervention against ISIS in Iraq at the request of Iraq, and intervention in Syria without the consent of the Assad government. They did not immediately join the operations in Syria.227 The USA was joined in Operation Inherent Resolve in Syria by four Gulf Arab states,228 but they did not offer any legal justification for their use of force and did not write to the Security Council under Article 51. From November 2014 the government of Syria protested against the coalition air strikes against ISIS in Syria. It said that ‘the air strikes cannot achieve their established goals if they are carried out in violation of the Charter of the UN and without cooperation and coordination with the Governments concerned—and if they are not accompanied by enjoining States that incite and support terrorism to stop their practices that violate the principles of international law’.229

In 2015 the US-led coalition was joined by Canada,230 Australia,231 and then France. The first two said they were acting to end ‘continuing attacks’ by ISIS. They used the language of ‘unwilling or unable’, but France did not. It simply invoked Article 51 in general terms.232 In July 2015, following a terrorist attack on its territory, Turkey also joined the campaign against ISIS in Syria, saying that the regime in Syria was ‘neither capable nor willing to prevent threats emanating from its territory which clearly imperil the security of Turkey and the safety of its nationals’. It invoked its inherent right of individual and collective self-defence, ‘as reflected in Article 51’ to respond to the clear and imminent threat of continuing attacks from ISIS.233 Syria strongly rejected Turkey’s claim to individual (p. 239) self-defence against ISIS in Syria, saying that Turkey had no right to invoke Article 51 because it was itself exporting the terrorism to which it referred.234

The November 2015 terrorist attacks on Paris drew more states into the Syrian conflict. In language reminiscent of 9/11, President Hollande proclaimed that France was at war. The Security Council met in response to the attacks and passed Resolution 2249 (2015) unanimously. This brief resolution determined (among other things) that ISIS—by its violent extremist ideology, its terrorist attacks, and also its control over significant parts of Iraq and Syria, and its recruitment and training of foreign terrorist fighters whose threat affects all regions and member states, even those far from the conflict zones—constituted a global and unprecedented threat to international peace and security. It noted Iraq’s letters stating that ISIS had established a safe haven outside Iraq’s borders. In the operative part, it noted that ISIS had the capacity and intention to carry out further attacks; it called upon member states to take all necessary measures, in compliance with international law, on the territory under the control of ISIS, to redouble and coordinate their efforts to prevent and suppress terrorist acts by ISIS and other terrorist groups associated with Al Qaida, and to eradicate the safe havens that it had established over significant parts of Iraq and Syria.

The Paris attacks were carried out by French and Belgian nationals, but France said that they were decided on, planned and prepared in Syria. This question of who is responsible for past terrorist attacks (or who is planning future terrorist attacks) is obviously crucial to the assessment of the legality of the response against a non-state actor in the territory of a non-complicit state and one to which it may be difficult to get a definitive answer. France spelled out in its speech to the Security Council that it would act in individual self-defence against ISIS.235 The French Legal Adviser François Alabrune made it clear that France regarded this as a special case.236 He recalled that the ICJ had in the Wall Opinion and DRC v Uganda taken a position that could be interpreted as limiting the right of self-defence to cases where there had been an armed attack by a state. France had reservations about the possibility of self-defence in response to non-state actors that were not attributable to a state. As for the response to 9/11 in Afghanistan, it was because of the substantial support given by the Taliban regime to Al Qaida that France had then invoked the right of collective self-defence. However, there were now special circumstances: the gravity of the attack,237 and the fact that ISIS controlled a very large area of territory and considerable resources, so that it could (p. 240) be described as a proto-state. Accordingly Alabrune said that ‘in the particular case and exceptionally’ there was no need to attribute the armed attack to a state in order to be able to invoke self-defence.

It is striking that none of the European states in their letters to the Security Council following the Paris attacks used the language of ‘unwilling or unable’. The UK letter was quite general.238 It said that ISIS was actively engaged in planning and directing attacks against the UK from Syria. ‘In accordance with Article 51’ it reported that it was taking necessary and proportionate measures against ISIS in Syria, as called for by the Council in Resolution 2249 (2015). Germany said that ISIS had occupied part of Syrian territory over which the Government of Syria did not at this time exercise effective control. ‘States that have been subjected to armed attack by ISIS originating in this part of Syrian territory are therefore justified under Article 51 of the Charter of the UN to take necessary measures of self-defence even without the consent of the Government.’ ISIS had carried out and continued to carry out armed attacks.239 Belgium used the same language as Germany, but also added that it was ‘in the light of this exceptional situation’ that states had the right of self-defence.240 Denmark, the Netherlands, and Norway all referred to Iraq’s letter and to Security Council Resolution 2249 as saying that ISIS had a ‘safe haven’ in Syria.241

Syria set out its response in letters to the Security Council.242 It accused the intervening states of ‘invoking a distorted reading of the intention of Article 51of the Charter of the UN, one that is blatantly inconsistent with the Charter and the resolutions of the Security Council,’ particularly those which emphasize that states must respect the unity, sovereignty, and territorial integrity of Syria. It said that they were violating international law and the UN Charter and distorting the meaning of this important and sensitive paragraph of the Charter in a manner that risks causing chaos and wars across the world. Syria had not made any request for those states to take action on its territory. The Syrian army was fighting terrorist groups; any actor that genuinely wishes to fight terrorism in Syria must coordinate with the Syrian armed forces. ‘If any State invokes the excuse of counter-terrorism in order to be present on Syrian territory without the consent of the Syrian government, whether on the country’s land or in its airspace or territorial waters, its actions shall be considered a violation of Syrian sovereignty.’ Russia similarly said that unilateral action against ISIS in Syria was a breach of Syrian sovereignty. The air strikes on Syria needed explicit consent by Syria.243

(p. 241) Apart from the fundamental questions about the legal basis of military action against ISIS in Syria without the government’s consent, there are certain problems with the application of the ‘unwilling or unable’ doctrine on the particular facts.244 First, Syria insisted that it was not ‘unwilling’ to take action against ISIS. It had always been willing to cooperate with others. It had repeatedly called on the international community to cooperate and coordinate with it fully and closely, but those calls had fallen on deaf ears. Instead some states had perverted the substance of Article 51 in order to violate the sovereignty of Syria.245 The Security Council resolutions, including Resolution 2178 (2014), on the terrorist threat in Syria had called for cooperation to counter terrorism. It seems that it was not so much the Syrian government that was unwilling to act against ISIS, but rather it was the USA’s hostility to the Syrian government that made it unwilling to cooperate with it. The French Foreign Minister Legal Adviser, François Alabrune, acknowledged that it was for political reasons that the consent of the Syrian government had not been sought.246 Second, it may be asked how far it is open to the USA to rely on Syria’s inability to act, in order to justify acting on its territory without its consent. It is at least arguable that it was the outside intervention by the USA, Turkey, Saudi Arabia, and Qatar, as well as certain European states, in support of the armed opposition against President Assad, that had contributed to the government’s loss of control of its territory and that had made it unable to act effectively against ISIS.247

More fundamentally, there are questions about the status and content of the legal doctrine invoked to justify the use of force in Syria, and in particular about the doctrine put forward by the USA. First, is the right to use force in self-defence against non-state actors in non-complicit states now firmly established?248 US State Department Legal Adviser Brian Egan asserts that the inherent right of (p. 242) self-defence recognized in the Charter is not restricted to threats posed by states, and that the right of self-defence on the territory of another state against non-state actors is not something that developed after 9/11. He claims that ‘for at least two hundred years’ states have invoked the right of self-defence to justify taking action on the territory of another state against imminent attacks by non-state actors.249 But it has been shown above that the position is not so clear. Before 9/11 there was very little support for such a right; the legal significance of 9/11 remains unclear; the post 9/11 incidents are not conclusive. The Non-Aligned Movement has regularly reaffirmed in general terms its position that Article 51 is a restrictive right and that it should not be rewritten or reinterpreted, but it has not commented on the specific case of Syria.250 For those states opposed to the US doctrine, there may be dangers in silence.251 Few states other than those critical of the USA (Cuba, Syria, Venezuela, Iran, Russia) are willing to speak out in express criticism of its use of force. Others only stress in general terms the need to comply with the Charter framework and to respect Syria’s sovereignty and territorial integrity (Brazil, South Africa, Chile, Spain, China).252 In its 2016 Foreign Policy Concept Russia said that it ‘views Article 51 of the UN Charter as providing an adequate legal basis for the use of force in self-defence that is not subject to revision, including the use of force in the face of threats to peace and security such as international terrorism and the proliferation of weapons of mass destruction’.253 It set out its intent ‘to counter attempts by some States or groups of States to revise the generally accepted principles of international law enshrined in the UN Charter … to counter politically motivated and self-interested attempts by some States to arbitrarily interpret the fundamental international legal norms and principle such as non-use of force or threat of force … to counter attempts to represent violations of international law as “creative” applications of such norms’.254

The Syrian conflict has brought more support for the legality of the use of force against non-state actors in a state that was not complicit in ISIS’s attacks on Iraq and other states. Major European states joined in the military operations or provided direct support, following the Paris terrorist attacks. But some of them (p. 243) have taken a cautious approach. Resolution 2249 (2015) following the Paris terrorist attacks made no mention of self-defence and left the questions of its scope and application open. It was clear that Resolution 2249 calling for states ‘to take all necessary measures’ was a crucial factor for several states; the UK, Germany, Belgium, Norway, and Netherlands all made express reference to it in their letters to the Security Council. France and Belgium stressed that this was an exceptional case. In the Security Council debate leading up to Resolution 2249, Russia said that ‘the French resolution is a political appeal, rather than a change to the legal principles underlying the fight against terrorism’.255 Chile stressed that ‘combating terrorism must take place in line with the obligations flowing from international law’, and Venezuela said that it was convinced that the fight against terrorism must be waged in the context of international cooperation under the binding international and regional instruments in this sphere. It hoped that the action taken under Resolution 2249 would always be coordinated with the countries concerned.256

As part of its doctrine of self-defence against non-state actors, the USA includes the ‘unwilling or unable’ test and a wide interpretation of imminence. Again these elements are more controversial than the USA indicates. The ‘unwilling or unable’ doctrine was claimed by the USA to be merely an application of the requirement that self-defence be necessary.257 But this doctrine is something more radical, and significantly extends the scope of self-defence.258 It came to prominence in the context of the US targeted killing programme. There is still little express support for this doctrine by states, even by those participating in the US-led Operation Inherent Resolve in Syria. It was only the USA, Canada, Turkey, and Australia that actually used this phrase in their letters to the Security Council. The first three all invoked the inherent right of self-defence ‘as reflected in’ Article 51. They are apparently relying on the controversial view that the previous wide right of customary international law self-defence survived the UN Charter, and that it is now possible to expand that customary law right of self-defence by reinterpretation of (p. 244) the meaning of the necessity requirement. Some commentators have made very wide claims about the amount of support in state practice for the ‘unwilling or unable’ doctrine, in that they rely on the practice of states not actually using this language as demonstrating commitment to this controversial doctrine.259 But the choice of words is important here because the ‘unwilling or unable’ doctrine brings with it special problems. It is true that certain states in justifying the use of force against non-state actors in Syria (or elsewhere) have used the language of ‘safe haven’ or lack of ‘effective control’ over a particular area in their letters to the Security Council,260 but these are distinct tests and they should not be identified with ‘unwilling or unable’: they do not require any assessment of whether a state is ‘unwilling or unable’ to take preventive action.

Given the controversy about the doctrine, it is clear that the decision not to use the language of ‘unwilling or unable’ in their communications to the Security Council ‘in accordance with Article 51’ must have been deliberate on the part of states such as the UK, France, and Germany. The UK later drew a distinction between the ‘many states’ it claimed supported a right to use force against non-state actors, and ‘some states’ that supported the unwilling or unable doctrine.261 Moreover, it seems that Iraq itself did not support the ‘unwilling or unable’ doctrine. Its letters to the Security Council inviting assistance against ISIS made no reference to ‘unwilling or unable’, but rather said that ISIS had established a ‘safe haven’ outside Iraq. And Iraq was not willing to accept Turkey’s claim that it was entitled to take action in self-defence against the PKK inside Iraq without Iraq’s consent: ‘Iraq strenuously opposes and condemns in the strongest possible terms any military movements aimed at countering terrorism that take place without prior consultation with the government of Iraq and without its approval.’262 It called on the Security Council to order Turkey to withdraw its forces.263 The Arab League condemned Turkey’s operations.264

Whether or not an expansive view of the extent of state support for the ‘unwilling or unable’ doctrine is taken, the doctrine is very problematic. It offers a wide discretion to the state relying on it. In 2012 Deeks argued persuasively that ‘the test’s lack of content undermines the legitimacy of the test as it currently is framed’ and (p. 245) said that it did not impose effective constraints on a state’s use of force; if such a doctrine were to be accepted, there would a need for clear limits, including the need to ask the host state for its consent first, to prioritize cooperation, to offer a full justification for the action, and to follow rigorous procedures.265 The 2016 Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations do not meet this need. As with other controversial doctrines purportedly justifying the use of force—humanitarian intervention and the protection of nationals abroad—this is a one-sided doctrine in that it is impossible to envisage it ever being invoked against the USA,266 or even against European states that have shown themselves to be unable to act against terrorists operating from their territory.

Who is to determine whether the host state is unwilling to act? The ‘unwilling’ element of the doctrine clearly calls for an assessment of the host state’s policy. The 2016 Frameworks suggested that unwillingness might be demonstrated where a state was colluding with or harbouring a terrorist organization and refused to address the threat posed by the group.267 However, there may be genuine policy differences between the intervening state and the host state as to whether a particular group are terrorists, as in the case of Lebanon where Hezbollah (classified as a terrorist organization by the USA, and also by the Arab League in 2016) is part of the government. There may also be a difference as to whether there is actually a terrorist threat to the USA, and as to how to respond to any such threat. This was an issue between the USA and Pakistan when Pakistan protested at the US targeted killings, saying that they were counter-productive in the war on terror; it denied that it was unable or unwilling to act.268 Similarly, Afghanistan challenged the USA’s counter-terrorism tactics on its territory—did this make it unwilling to act against Al Qaida or the Taliban?

As regard the alternative basis for action—that the host state is ‘unable’ to act—the 2016 Frameworks suggest that this could be demonstrated most plainly where a state has lost or abandoned control over the portion of territory where the armed group is operating. The US position is that there is no need to seek consent if a state is unwilling or unable to act against terrorists. But just because a state is unable to act in certain areas this does not mean that its consent to act against an armed group in those areas cannot be sought. This part of the US doctrine does not seem compelling. Another question about this criterion is whether a (p. 246) state could always be regarded as unable to act if there have in fact been terrorist attacks from its territory.

The USA claims that the ‘unwilling or unable’ doctrine is merely part of the necessity requirement and that it limits the right to use force in self-defence, but in reality the doctrine goes beyond this. It is open to the objection that it actually enables the use of force, that the USA uses the ‘unwilling or unable’ doctrine as a trigger for action, not as a limit on action. Its approach is different from that of the ICJ which consistently examined the question of necessity after it had established whether there was a right of self-defence; it then looked at necessity to limit the exercise of such a right. Moreover, when the ‘unwilling or unable’ doctrine is combined with the argument that self-defence is lawful against an imminent attack—imminent as very broadly construed by the USA with regard to targeted killing and the conflict in Syria—then the USA can expand its right of self-defence even further. Finally, the USA also argues that there is no need to show that each use of force is against an imminent attack, provided that hostilities continue.269 This is the same argument as it had made in the context of targeted killing; it runs together ius ad bellum and ius in bello in such a way as to give itself a continuing right of self-defence. Given that Security Council Resolution 2249 determined that ISIS had the capability and intention to carry out further attacks, the question arises (as it had earlier with the continuing counter-terrorism operations against Al Qaida inside and outside Afghanistan following the terrorist attacks of 9/11) what end there can be to such a conflict. Moreover, the 2016 Frameworks do not set out any constraints on the ‘unwilling or unable’ doctrine. This looks like a fundamental change in the right of self-defence of such a far-reaching nature that it would need overwhelming support if it is to be accepted as international law.

Those states who put forward the ‘unwilling or unable’ doctrine to justify self-defence against non-state actors do not make clear how it is to be reconciled with the principle of the equality of states and the prohibition of the use of force against member states in the UN Charter, or with the many Security Council resolutions on the Syrian conflict that call for respect for Syria’s sovereignty and territorial integrity. The 2016 Frameworks simply assert that applying the standard ensures that the sovereignty of other states is respected. ‘Specifically, applying the standard ensures that force is used on foreign territory without consent only in those exceptional circumstances in which a State cannot or will not take effective measures to confront a non-state actor that is using the State’s territory as a base for attacks and related operations against other States.’270 (p. 247) Some of the states using force in Syria claimed that they were acting only against a non-state actor, ISIS, and not against the host state, Syria. Thus, Canada, Australia, Norway, and Belgium all said that their military actions were not aimed at Syria or the Syrian people, nor did they entail support for the Syrian regime. This type of claim is reminiscent of earlier arguments that the prohibition in Article 2(4) has only a limited scope.271 Syria rejected such arguments and protested further that the coalition had targeted its state infrastructure rather than just ISIS.272 In 2017 it protested again when the USA shot down a Syrian jet.273

A large amount has been written on the ‘unwilling or unable’ doctrine as part of self-defence against non-state actors.274 Some examine the state practice;275 others suggest limitations on the doctrine;276 a few writers have attempted to rationalize the doctrine, to offer a legal basis for the argument that is compatible with the UN Charter prohibition on the use of force against member states. Two main approaches have been put forward, sometimes in combination.277 The first argument is that, if a state is unwilling or unable to act against terrorists, then it is actually complicit in their attacks and those attacks may be attributed to it, thus allowing a response against its territory. That is, the ‘unwilling or unable’ test is to be seen as part of attribution under the law of state responsibility, and is relevant to the question who is the author of an attack. However, this not the US position. Second, it is claimed that a state may lose its rights under Article 2(4) if it has broken its duties of due diligence or violated other international legal obligations with regard to acquiescence in the activities of armed groups on its (p. 248) territory.278 If a state is unwilling or unable to act, then it is in violation of these duties. However, this does not seem to be compatible with the reasoning of the ICJ in Corfu Channel that a breach of the duty of due diligence by Albania did not justify the use of force by the UK.279 Nor is it compatible with the judgment in DRC v Uganda that the DRC’s inability to control the attacks of rebel groups on its territory against Uganda did not violate the duty of vigilance, and that Uganda was not entitled to use force against the DRC.280

The ‘unwilling or unable’ doctrine was put forward by the USA in the context of targeted killings of individual terrorist suspects. It is now being expressly adopted by a small number of states with regard to a more traditional conflict, involving the use of force in collective self-defence of Iraq to secure control of territory from ISIS in Syria. It is still too early to assess whether this doctrine will gain the widespread support necessary to transform the right of self-defence in such a radical fashion. It can also be asked whether the wide view of imminence put forward by the USA and the UK will also be applied in other contexts, including the use of force to prevent the proliferation of weapons of mass destruction.

The Bush Doctrine of Pre-Emptive Self-Defence

Another question arising out of 9/11 and its aftermath was whether self-defence against terrorist attacks is permissible only when there has been an actual past attack or whether a purely pre-emptive action is lawful, and if so, how such a pre-emptive action could be necessary and proportionate. Moreover, would pre-emptive action be legal only against terrorism or also against other dangers such as proliferation of weapons of mass destruction? This question is still important today—despite the apparent abandonment of the language of pre-emptive self-defence in favour of a very wide interpretation of ‘imminence’—because of the US refusal to rule out the use of force against North Korea under President Obama, and the intemperate threats of force by President Trump in 2017, of Israel’s continuing threats of force against Iran, and of the uncertainty over US policy towards Iran under President Trump.

The USA in its letter to the Security Council under Article 51 at the start of Operation Enduring Freedom (2001) said that, ‘In response to these attacks and in accordance with the inherent right of individual and collective self-defence, United States armed forces have initiated actions designed to prevent and deter (p. 249) further attacks on the United States.’281 The UK letter said, ‘These forces have been employed in exercise of the inherent right of individual and collective self-defence, recognized in Article 51, following the terrorist outrage of 11 September, to avert the continuing threat of attacks from the same source.’282 These are claims to preventive and deterrent action which before 9/11 would have been regarded by many as unlawful reprisals rather than lawful self-defence, but even these wide claims were limited by the fact that there had been an actual attack. The apparent attempt by the USA subsequently to extend the right of self-defence to cover purely pre-emptive action against non-imminent attacks has proved extremely controversial.283

In his State of the Union Address in January 2002, President Bush said that the ‘war against terrorism’ was just beginning. Although Operation Enduring Freedom in Afghanistan was far from over, he shifted the focus of the war towards the ‘Axis of Evil’ consisting of Iraq, Iran, and North Korea. His concern was that these states were developing weapons of mass destruction which they might use themselves or supply to terrorist organizations hostile to the USA. It was with regard to these states that the question of pre-emptive self-defence came to the fore. The USA in September 2002 produced a National Security Strategy in response to the new terrorist threat.284 It warned: ‘While the US will constantly strive to enlist the support of the international community, we will not hesitate to act alone if necessary, to exercise our right of self-defense by acting pre-emptively against such terrorists, to prevent them from doing harm against our people and our country.’

The USA was now putting forward a new ‘Bush doctrine’, extending the right of self-defence far beyond its traditional scope.285 The USA must be prepared to stop rogue states and their terrorist clients before they are able to threaten to use weapons of mass destruction. ‘Given the goals of rogue states and terrorists, the US can no longer rely on a reactive posture as we have in the past. The inability to deter a potential attacker does not permit that option. We cannot let our (p. 250) enemies strike first … We must be prepared to stop rogue states and their terrorist clients before they are able to threaten or use weapons of mass destruction against the US. The doctrine of self-defense needs to be revised in the light of modern conditions. In particular the requirement that a threat be imminent needs to be revisited.’

This apparent attempt to extend the war against terrorism to cover purely pre-emptive action in the absence of an imminent attack (or even an imminent threat) provoked much controversy. President Bush seemed to be taking advantage of the rhetoric of the ‘war against terrorism’ and the legitimacy conferred by that war to stretch the boundaries of self-defence. There was some uncertainty as to the exact scope of the US claims. The terms anticipatory, preventive and pre-emptive are not technical terms of art with clear meanings and they are used in different ways by different authors. But the crucial question of substance was that the USA was claiming a right to use force against non-imminent attacks. This was the UK Attorney-General’s understanding of the US position. In his advice on the legality of the use of force against Iraq, he said, ‘I am aware that the USA has been arguing for recognition of a broad doctrine of a right to use force to pre-empt danger in the future. If this means more than a right to respond proportionately to an imminent attack (and I understand that the doctrine is intended to carry that connotation) this is not a doctrine which in my opinion exists or is recognized in international law.’286 The opposition by many states to Operation Iraqi Freedom (2003) made it clear that they were not willing to accept pre-emptive self-defence as a legal basis for that particular action.

The High-level Panel Report and the Secretary-General’s Report In Larger Freedom both expressly rejected the doctrine of pre-emptive self-defence which they understood as action against non-imminent threats. These reports addressed the issue whether the right of self-defence should be expanded to meet the new threats facing the world. Although both reports controversially accepted anticipatory self-defence against an imminent attack, they were not prepared to go any further. Where the threat is not imminent—for example, the acquisition of nuclear weapons-making capacity—a state cannot act pre-emptively against a non-imminent or non-proximate threat. In such a situation it was for the UN Security Council to authorize action. Unilateral pre-emptive action posed too great a threat to global order.287 Nor was there any widespread support by states for the ‘Bush doctrine’.288 Nevertheless, the USA strongly rejected the position (p. 251) of the High-level Panel Report,289 and in 2006 it issued a new National Security Strategy repeating its commitment to pre-emptive self-defence.290 It said, ‘The place of pre-emption in our national security strategy remains the same’ and it reaffirmed all the relevant sections of the 2002 Strategy on the use of force. But its identification of the nature of the threat in the war on terror had shifted since 2002: the main danger was now said to come from ‘Islamic extremists’,291 and it was now Iran and Syria (rather than Iraq and North Korea) which posed the greatest threat as ‘sponsors of terror’.292

The 2006 Strategy, like its predecessor, left many questions about pre-emption unanswered. It did not make clear what would trigger the right of pre-emptive action and what is the proper scope of such action. It repeated the words of the 2002 Strategy that ‘under long-standing principles of self-defense we do not rule out the use of force before attacks occur, even if uncertainty remains as to the time and place of the enemy’s attack,’293 and added only that, ‘The reasons for our actions will be clear, the force measured, and the cause just.’ There was no further discussion of the imminence requirement. Indeed there was no mention of international law in the 2006 Strategy and almost no mention of the role of the UN in the maintenance of international peace and security.

There was very little international support for this doctrine of pre-emptive self-defence.294 The General Assembly debates on In Larger Freedom showed that most states were not willing to accept anticipatory, let alone pre-emptive, self-defence.295 The Non-Aligned Movement of over one hundred states has repeatedly rejected the doctrine of pre-emptive self-defence.296 NATO, which had been given only very limited mention in the 2002 and the 2006 US National Security Strategy, did not openly adopt the Bush doctrine of effectively unlimited self-defence, and nor did the EU.297

(p. 252) As was described in Chapter 4, the ICJ has avoided any pronouncement on anticipatory self-defence. But in Armed Activities on the Territory of the Congo (DRC v Uganda) Uganda in invoking its right to self-defence against an armed attack had argued that its use of force was necessary ‘to secure its legitimate security interests’. The Court said that the specified security interests were essentially preventative—to ensure that the political vacuum in the border area did not adversely affect Uganda, to prevent attacks from genocidal elements, to be in a position to safeguard Uganda from irresponsible threats of invasion, and to deny the Sudan the opportunity to use the territory of the DRC to destabilize Uganda.298 Later in the judgment the Court said ‘Article 51 of the Charter may justify the use of force in self-defence only within the strict confines there laid down. It does not allow the use of force by a State to protect perceived security interests beyond these parameters. Other means are available to a concerned State, including, in particular, recourse to the Security Council.’299 The Court therefore indicated that it would not accept pre-emptive action as self-defence.

In his 2010 National Security Strategy, President Obama left the question open.300 It seems from US practice on targeted killing and its legal argument to justify intervention in Syria that the USA now prefers to stretch the meaning of ‘imminence’ rather than expressly to avow a doctrine of pre-emptive self-defence. Even the UK government, often the USA’s strongest supporter, never accepted a doctrine of pre-emptive self-defence.301 In 2004 the Attorney-General said: ‘It is therefore the Government’s view that international law permits the use of force in self-defence against an imminent attack but does not authorise the use of force to mount a pre-emptive strike against a threat that is more remote.’302 However, the UK seems to have adopted a wide conception of imminence: ‘The concept of what constitutes an imminent attack will develop to meet new circumstances and new threats. For example, the resolutions passed by the Security Council in the wake of 11 September 2001 recognised both that large-scale terrorist action could constitute an armed attack that will give rise to the right of self-defence and that (p. 253) force might, in certain circumstances, be used in self-defence against those who plan and perpetrate such acts and against those harbouring them, if that is necessary to avert further such terrorist attacks. It was on that basis that UK forces participated in military action against Al’Qaida and the Taliban in Afghanistan. It must be right that states are able to act in self-defence in circumstances where there is evidence of further imminent attacks by terrorist groups, even if there is no specific evidence of where such an attack will take place or of the precise nature of the attack.’303

The UK Attorney-General elaborated on this in 2017, adopting the same approach as the US State Department Legal Adviser, Brian Egan: the imminence of an attack by non-state actors is to be determined by a list of factors including not only the nature and immediacy of the attack, but also the probability of an attack, whether there is a pattern of continuing armed activity, the likely scale of the attack and the injury likely to result, and the likelihood that there will be other opportunities to take action in self-defence. Thus, imminence in time is no longer an essential requirement. Such a wide conception of imminence does not seem to provide any significant constraint on the use of force. Nevertheless, the UK Attorney-General was careful to stress that ‘the approach I am setting out … is a very long way from supporting any notion of a doctrine of pre-emptive strikes against threats that are more remote … It is absolutely not the position of the UK government that armed force may be used to prevent a threat from materialising in the first place’.304

Iraq and Pre-Emptive Self-Defence

After President George W Bush’s State of the Union Address in January 2002,305 with its destabilizing rhetoric about the threat from Iran, Iraq, and North Korea (the ‘Axis of Evil’), most discussion of the precedential significance of the action against Afghanistan focused on the question how far the use of force against Iraq could be justified as part of the war against terrorism, or whether some other justification would be used.306 In their apparent determination to embark on the use of force against Iraq, in response to its repeated violations of the ceasefire regime established in Security Council Resolution 687 (1991) and its non-cooperation with UN weapons inspectors, some members of the US administration made claims of links between Al Qaida and President Saddam Hussein of Iraq.307 But (p. 254) intelligence agencies in the USA and the UK were unable to identify any significant link between Al Qaida and Saddam Hussein. They acknowledged that Saddam Hussein had no involvement in the Al Qaida attacks on the WTC and Pentagon.308 Nevertheless, the US administration made renewed claims of a link immediately before the use of force against Iraq.309

In the period between 9/11 and the eventual attack on Iraq in March 2003 there were deep divisions between states on whether to use force against Iraq and whether there was any legal justification for Operation Iraqi Freedom.310 Many states warned that an invasion of Iraq would be a dangerous distraction from the ‘war on terror’. They expressed serious doubts about the Axis of Evil rhetoric of the USA, and the attempt to extend the war against terrorism to prevent certain states developing weapons of mass destruction.311 NATO states were bitterly divided; they produced only a cautious declaration on Iraq in the November 2002 Prague Summit Statement with no commitment to the use of force, let alone to the doctrine of pre-emption.312

For those states supporting action against Iraq, the crucial question became whether such an action could be a use of pre-emptive self-defence. Or, alternatively, should action against Iraq be justified on the basis of non-compliance with the ceasefire regime binding on Iraq under Resolution 687 (1991) and subsequent resolutions? Or, as is characteristic of legal argument, it might be that a combination of these weak arguments would be used. It is interesting that the Resolution of the US Houses of Congress in October 2002 used both implied authorization and self-defence. This ‘Authorization for the Use of Military Force against Iraq’ authorized the President ‘to use the armed forces of the United States as he determines to be necessary and appropriate in order to (1) defend the national security of the United States against the continuing threat posed by Iraq; and (2) enforce all relevant United Nations Security Council Resolutions regarding Iraq’.313 Clearly the USA was deliberately keeping both options open. President Bush’s address to the Nation on 19 March 2003 as military operations against Iraq began and the US letter to the Security Council under Article 51 on 20 March 2003 also used this combination of arguments.

(p. 255) But the UK and Australia, the only other states to contribute forces to Operation Iraqi Freedom, did not use pre-emptive self-defence as any part of their legal case for the invasion of Iraq; they preferred to rely on authorization by the Security Council, an indication of the doubt over the doctrine of pre-emptive action.314 Nor did the other states offering military or political support expressly put forward a justification based on pre-emption.315 Several states which opposed the use of force against Iraq expressly rejected the legality of pre-emptive use of force.316

Any case for pre-emption rested on the existence of a threat of attack on the USA and others arising from Iraq’s possession or development of weapons of mass destruction. But the problems with this doctrine were apparent when the US and UK case for forcible action against Iraq was challenged by other states. Germany, France, Russia, and China all preferred to continue the UN weapons inspections established under the ceasefire regime in Resolution 687 (1991) and reintroduced in November 2002 under Resolution 1441 to secure the disarmament of Iraq; they did not accept the existence of an imminent threat.317 And even within the USA and the UK there were reports that the intelligence services did not accept that Iraq posed an imminent threat to their states.318 In the absence of any imminent threat, force could be used in self-defence only under a very wide ‘Bush doctrine’. Although the USA referred to the need to defend the USA as a possible basis for Operation Iraqi Freedom, it did not go into detail as to the scope of this doctrine; the UK and Australia placed no reliance on pre-emptive self-defence.

After Operation Iraqi Freedom drove Saddam Hussein from power in Iraq in April 2003, the US and UK occupying forces did not find WMD. In both the USA and the UK there was debate over the intelligence data on the basis of which the case for the use of force against Iraq was made; in both the USA and the UK (and in Australia) there were serious political concerns as to whether the governments had deliberately misled their people as to the nature of the threat posed by Iraq and as to the case for the use of force.319 The Iraq Survey Group, formed in May 2003 to hunt for WMD in Iraq, stated in its final report that after 1,500 (p. 256) inspectors had spent sixteen months in searching Iraq they had not unearthed any WMD or any programmes to manufacture them.320 It is generally agreed that Al Qaida did not operate in Iraq before Operation Iraqi Freedom, but it began to do so afterwards, and eventually transformed itself into ISIS.321

Thus pre-emptive self-defence remains extremely problematic. The doctrine as set out by the USA in its 2002 and 2006 National Security Strategies is not clear; it contains a central uncertainty as to what will trigger pre-emptive action, what form pre-emptive action will take and as to the role envisaged for the UN, if any.322 A clear split emerged among those states which had supported the attack on Afghanistan as to whether to go further and act against Iraq. Although about forty-five states were willing to offer military or political support to the USA in its use of force against Iraq, it seems that none did so on the basis of the doctrine of pre-emptive self-defence. The move away from response to past terrorist attacks to possible armed action against states in alleged possession of WMD who might give them to terrorists, the stress on military rather than peaceful mechanisms and on unilateral rather than multilateral decisions on the existence and seriousness of a threat were not acceptable to many states and commentators.323 Many argued that concern over the spread of nuclear weapons should be addressed through existing multilateral treaties. The UN Deputy Secretary-General acknowledged the fear of how much more damage terrorists could do if they were to acquire WMD, but stressed the importance of a multilateral approach through the Non-Proliferation Treaty:

If the competition of nuclear-armed super-Powers was terrifying, so—in a different way—is the thought of such weapons in the hands of terrorists … Here too we have a number of international instruments which have undoubtedly played an important part in restraining the spread of such weapons. Particularly important is the Nuclear Non-Proliferation Treaty … The vast majority of States appear to value the treaty, and to respect its provisions. But this acceptance is gradually being undermined as non-nuclear-weapon states hear nuclear-weapon states propounding doctrines of first use; as they see new nuclear weapons being used; and as reduction of existing weapons stocks proceeds more slowly than had been hoped.324

(p. 257) The Next Steps: Iran and North Korea

The rhetoric of pre-emption was employed by the USA in order to put pressure not only on Iraq, but also on Iran and North Korea—states which the USA saw as a potential threat because of their possible development of weapons of mass destruction and because of the alleged risk that they might provide such weapons to terrorists hostile to the USA. The USA’s unfriendly language towards these states since President Bush’s Axis of Evil speech in January 2002 gave rise to speculation that the USA was planning to use pre-emptive force to prevent their development of nuclear weapons.325 The 2002 US National Security Strategy focused on the threat posed by Iraq, Iran, and North Korea. The UN Secretary-General warned that the development of a policy calling for pre-emptive and, if necessary, unilateral action against the threat of WMD was a challenge to the existing multilateral treaty regimes on disarmament and arms limitation.326 In particular the nuclear non-proliferation regime faced a major crisis of confidence. India, Israel, and Pakistan had never joined the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and had all developed nuclear weapons, North Korea had withdrawn from the treaty, and there were concerns about Iran’s nuclear programme. States had been unable to strengthen the NPT because they could not agree whether non-proliferation or disarmament should come first.327

North Korea

The USA initially adopted extremely hostile rhetoric towards North Korea when President Bush took power, denouncing it as a member of the ‘Axis of Evil’, and expressing concern about its possible acquisition of nuclear weapons.328 This decline in relations brought to an end the 1994 US/North Korea Agreed Framework,329 concluded after North Korea had threatened to withdraw from the NPT in 1993.330 Under this agreement North Korea had agreed to freeze its nuclear weapons programme in exchange for US aid for the production of peaceful nuclear energy and oil supplies. The decline in relations also undermined the improvement in relations between North and South Korea and led to (p. 258) concern among the states of the region.331 In response North Korea proclaimed the existence of its nuclear weapons programme in October 2002, stepped up its nuclear programme, and in January 2003 announced its withdrawal from the NPT.332 The USA on several occasions threatened pre-emptive action (or refused to rule it out) to stop North Korea from developing nuclear weapons.333 North Korea said that it was therefore entitled to take a pre-emptive strike against the USA because of US threats and that it had withdrawn from the NPT as a measure of legitimate self-defence in face of US threats.334 North Korea demanded a non-aggression pact with the USA in return for easing security tensions.335

Attempts to negotiate a settlement proved fruitless. In its 2006 National Security Strategy the USA stated that the tyrannical regime in North Korea was defying the international community in its illicit nuclear programme.336 In 2006 North Korea test fired long-range ballistic missiles, a possible future delivery system for nuclear weapons. In response the Security Council unanimously passed Resolution 1695 (2006), its first resolution on North Korea since 1993. This deplored North Korea’s announcement of withdrawal from the NPT and its stated pursuit of nuclear weapons. It condemned the launch of the ballistic missiles, ‘given the potential of such systems to be used as a means to deliver nuclear, chemical or biological payloads’. North Korea said in reply that the launches were part of routine military exercises to increase its military capacity for self-defence.337

North Korea then took the dramatic step of carrying out its first nuclear weapons test in October 2006. It said: ‘The US extreme threat of a nuclear war and sanctions and pressure compel the DPRK to conduct a nuclear test, an essential process for bolstering nuclear deterrent, as a self-defence measure in response.’338 The Security Council in Resolution 1718 (2006) condemned the test, demanded that North Korea return to the NPT, and decided that it must abandon its nuclear weapons and its ballistic missiles programmes; in order to secure compliance with these demands it imposed sanctions on North Korea.339 North Korea rejected the resolution: ‘It is gangster-like of the Security Council to have adopted today a coercive resolution while neglecting the nuclear threat and moves for sanctions and pressure of the United States against the DPRK.’340 (p. 259) North Korea accused the Security Council of double standards, saying that it was disappointed that the Council was incapable of offering a single word of concern when the USA threatened to launch pre-emptive nuclear attacks, reinforced its armed forces and conducted large-scale military exercises near the Korean peninsula. It had felt compelled to prove its possession of nuclear weapons to protect itself from the danger of war from the USA. Some interpret this episode as a demonstration of the counter-productive impact of threats of pre-emptive self-defence: they, coupled with calls for regime change, provided a perverse incentive to acquire WMD.

This pattern has continued since 2006. North Korea has carried out a series of nuclear weapons tests—now six in total, with the largest in September 2017—and has launched several long range missiles; the Security Council has repeatedly condemned such actions.341 North Korea has sent a series of letters to the Security Council asserting a right of pre-emptive self-defence in response to the USA’s refusal to rule out the use of force.342 Recently it wrote that, ‘During the past five years, the US revealed its intention to deliver a pre-emptive nuclear strike against the DPRK and intensified its military threats against us at a maximum pace… The desperate hostile policy of the US towards the DPRK gave rise to the self-defensive measures from the latter… The DPRK has chosen the road of possessing nuclear weapons as a self-defensive measure to safeguard its State and system from the constant nuclear threat of the US.’343 The USA and North Korea repeated their intemperate and provocative threats against each other at the plenary session of the UN General Assembly in September 2017.


The USA also repeatedly expressed concern that Iran was developing a nuclear weapons programme.344 In the 2006 US National Security Strategy it said that Iran harboured terrorists at home and sponsored terrorist activity abroad. The USA was concerned about Iran, not only because of its attempts to develop nuclear weapons, but also because of broader concerns: ‘The Iranian regime sponsors terrorism, threatens Israel, seeks to thwart Middle (p. 260) East peace, disrupts democracy in Iraq; and denies the aspirations of its people for freedom.’345

Iran maintained that it was merely working to develop peaceful nuclear energy as it was entitled to under the NPT to which it was a party. It claimed a legal right to develop a uranium enrichment programme for civil nuclear purposes under the oversight of the International Atomic Energy Authority (IAEA). The Non-Aligned Movement supported this legal right.346 The USA and other Western states opposed any Iranian uranium enrichment programme as this would allow Iran to produce weapons-grade uranium. Prolonged negotiations failed to resolve this dispute. In September 2005 the IAEA found Iran in non-compliance with its NPT obligations, and in February 2006 it referred the matter to the Security Council.347 In April 2006 Iran claimed it had successfully enriched uranium.348 The Security Council demanded in Resolution 1696 (2006) that Iran suspend enrichment-related activities, to be verified by the IAEA. When the IAEA reported that Iran had not taken the steps required by the IAEA the Security Council imposed sanctions in Resolution 1737 (2006) and a series of subsequent resolutions.

The language of these resolutions was deliberately very cautious; there is nothing to authorize unilateral use of force.349 But there were many reports that some in the US administration were determined to pursue pre-emptive military action against Iran to prevent its acquisition of nuclear weapons capacity. President Bush refused to rule out the use of force against Iran,350 and continued to assert that Iran remained a dangerous threat.351 Iran complained to the Security Council about ‘the daily threats of resort to force against Iran, even the threat of using nuclear weapons, uttered at the highest levels by the US, UK and the lawless Israeli regime in violation of Article 2(4) of the Charter’.352 The USA under President Obama pursued a negotiated settlement with Iran, but it did (p. 261) not rule out the use of force. It did not provide an express legal basis for this position.353 Israel also made veiled threats of unilateral military action to prevent Iran from acquiring nuclear weapons capacity,354 and Iran reported these threats to the Security Council.355 The USA and Israel turned to cyber-warfare, including the Stuxnet attacks, as a means of sabotaging Iran’s nuclear programme.356 Israel also carried out targeted killings of Iranian nuclear scientists in Iran.357 Finally a negotiated settlement was reached in a Joint Comprehensive Plan of Action between Iran, the USA, the five permanent member states of the Security Council, Germany, and the EU in July 2015.358 However, President Trump’s hostility towards this settlement means that the situation is once again precarious.

The doctrine of pre-emptive self-defence apparently allowed the USA to make plausible threats against what it regards as rogue states to prevent them from acquiring nuclear weapons capacity, while maintaining lip-service to international law. But the problems were obvious: these threats went far beyond the traditional conception of self-defence and beyond the force used in Operation Enduring Freedom. The responses of North Korea made clear the dangers of escalation inherent in the doctrine of pre-emptive action. France in particular had earlier warned of the dangers of the doctrine of pre-emptive self-defence: ‘As soon as one nation claims the right to take preventive action, other countries will naturally do the same. And what would you say, in the entirely hypothetical event that China wanted to take preventive action against Taiwan, saying that Taiwan was a threat to it? How would the Americans, the Europeans and others react? Or what if India decided to take preventive action against Pakistan, or vice versa?’359 The USA has now apparently abandoned the language of pre-emption, but its wide doctrine of ‘imminence’ may mean that in substance its position is much the same. It remains to be seen whether it will attempt to extend this doctrine beyond counter-terrorism to non-proliferation of WMD.


1  For an account of the events, see Murphy, ‘Contemporary Practice of the United States relating to International Law’, 96 AJIL (2002) 237 and Keesing’s (2001) 44333, 44391.

2  President Obama rejected the term ‘war on terror’ in 2009, but asserted instead that the USA was at war with Al Qaida, a ‘network of violence and hatred’. See Gray, ‘President Obama’s 2010 National Security Strategy and international law on the use of force’, 10 Chinese JIL (2011) 35. President Trump carried out his first targeted killings (in Yemen) in the first days of his term of office.

3  Murphy, ‘Contemporary Practice of the United States relating to International Law’, 96 AJIL (2002) 237 at 239; O’Connell, ‘Evidence of Terror’, 7 JCSL (2002) 19.

4  SC Res 1368 (2001) and 1373 (2001); GA Res/56/1 (2001).

5  See 176 above.

6  40 ILM (2001) 1270, 1273. See also Ratner, ‘Ius ad bellum and ius in bello after September 11’, 96 AJIL (2002) 905 at 909.

7  Murphy, ‘Contemporary Practice of the United States relating to International Law’, 96 AJIL (2002) 237 at 248.

8  Keesing’s (2001) 4435–6, 44393.

9  Murphy, ‘Contemporary Practice of the United States relating to International Law’, 96 AJIL (2002) 237 at 243; Keesing’s (2001) 44337.

10  Keesing’s (2001) 44391, 44448; Murphy, ‘Contemporary Practice of the United States relating to International Law’, 96 AJIL (2002) 237 at 246; Katselli and Shah, ‘September 11 and the UK Response’, 52 ICLQ (2003) 245; Byers, ‘Terrorism, the Use of Force and International Law after 11 September 2001’, 51 ICLQ (2002) 401.

11  UN docs S/2001/946, S/2001/947; 40 ILM (2001)1280.

12  Press Release, Brussels, 7 October 2001.

13  Keesing’s (2014) 53743.

14  Combating Terrorism, A Policy Report of the UN Association of the USA, (2002) at 23.

15  For example, Reinold, ‘State weakness, irregular warfare and the right to self-defense’, 105 AJIL(2011) 244; Tams, ‘The use of force against terrorists’, 20 EJIL (2009) 359.

16  See 237 below.

17  Alexandrov, Self-Defense against the Use of Force in International Law (1996) at 182; Arend and Beck, International Law and the Use of Force: Beyond the UN Charter Paradigm (1993) at 138; O’Brien, ‘Reprisals, Deterrence and Self-Defense in Counterterror Operations’, 30 Virginia JIL (1990) 421.

18  1968 UNYB 228. See Falk, ‘The Beirut Raid and the International Law of Retaliation’, 63 AJIL (1969) 415; Blum, ‘The Beirut Raid and the International Double Standard’, 64 AJIL (1970) 73.

19  1985 UNYB 285; UN docs S/PV 2610, S/PV 2615 (1985).

20  1986 UNYB 247; the USA reported to the Security Council in UN doc S/17990, 14 April 1986; UN docs S/PV 2677, S/PV 2679, S/PV 2680 (1986); see ‘Contemporary Practice of the US’, 80 AJIL (1986) 632; on UK position see ‘UK Materials on International Law’, 57 BYIL (1986) 641. Greenwood, ‘International Law and the United States Air Operation Against Libya’, 89 West Virginia Law Review (1987) 933.

21  The USA denied that there was any parallel between the South African attacks on Zambia, Zimbabwe, and Botswana and its own acts against Libya; the UK apparently accepted this, ‘UK Materials on International Law’, 57 BYIL (1986) 621, but other states said there was such a parallel between the actions of the USA and of South Africa, UN docs S/PV 2684, S/PV 2686 (1986).

22  UN doc S/PV 3245 (1993)

23  ‘UK Materials on International Law’, 64 BYIL (1993) 732.

24  UN doc S/PV 3245 (1993); 1993 UNYB 431; US letter to the Security Council UN doc S/26003, 26 June 1993; Kritsiotis, ‘The legality of the 1993 US Missile Strike on Iraq and the right of self-defence in international law’, 45 ICLQ (1996) 162; Gray, ‘After the Cease-fire: Iraq, the Security Council and the Use of Force’, 65 BYIL (1994) 135; Reisman, ‘The raid on Baghdad: some reflections on its lawfulness and implications’, 5 EJIL (1994) 120; Condorelli, A propos de l’attaque américaine contre l’Iraq du 26 Juin 1993’, 5 EJIL (1994) 134.

25  UN doc S/1998/780; 1998 UNYB 1218.

26  ‘Contemporary Practice of the United States relating to International Law’, 93 AJIL (1999) 161. There was considerable doubt as to whether the plant in Sudan was really a chemical weapons factory linked to international terrorism, Keesing’s (1999) 42766. The UK position showed some uncertainty; the PM defended the legality of the US action but the Foreign Secretary took a much more cautious line. It is noteworthy that the UK Materials on International Law for BYIL (1998), prepared with the help of the UK Foreign and Commonwealth Office (FCO), do not include any materials on the UK reaction.

27  Once again writers have gone further than states in claiming that it is unrealistic to outlaw reprisals. Some have tried to argue that certain reprisals may be legitimate, although technically illegal. Bowett was the first to make this claim with regard to Israel. He said that failure to condemn by the Security Council was an indication that the action was permissible, Bowett, ‘Reprisals involving recourse to armed force’, 66 AJIL (1972) 31. O’Brien followed this line and updated it, O’Brien, ‘Reprisals, Deterrence and Self-Defense in Counterterror Operations’, 30 Virginia JIL (1990) 421. But this argument was forcefully and successfully refuted by Barsotti, ‘Armed Reprisals’, in Cassese (ed), Current Legal Regulation of the Use of Force (1986) 79.

28  For example, Cassese, ‘Terrorism is also disrupting some crucial legal categories of international law’, 12 EJIL (2001) 993; Myjer and White, ‘The Twin Towers Attack: an Unlimited Right to Self-defence’, 7 JCSL (2002) 5.

29  For conflicting interpretations of the drafting history, see Murphy, ‘Terrorism and the concept of armed attack in Article 51 UN Charter’, 2002 (43) Harvard ILJ 41; Hamid, ‘The legality of anticipatory self-defence’, 54 Neth ILR (2007) 441.

30  See 226 below.

31  In the pre-9/11 incidents discussed above the states against whom action was taken in response to prior terrorist acts were all accused of involvement in the terrorism, with the exception of Tunisia. Israel’s attack on Tunis in 1985 was condemned by the Security Council (see note 19 above).

32  Nicaragua case, ICJ Reports (1986) 14 at para 195.

33  Murphy, ‘Contemporary Practice of the United States relating to International Law’, 96 AJIL (2002) 237.

34  Pub. L. 107–40, 40 ILM (2001)1282.

35  UN doc S/2001/946; 40 ILM (2001)1280.

36  FCO Paper, Responsibility for the terrorist atrocities (2001).

37  UN doc S/2001/947.

38  Attorney-General Speech in the House of Lords, HL Debates, 21 April 2004, Vol 660, c369–72; UK Materials in International Law, 75 BYIL (2004) 822–3.

39  Ratner, ‘Ius ad Bellum and Ius in Bello after September 11’, 96 AJIL (2002) 906. The 2005 AU Non-Aggression and Common Defence Pact (entered into force in 2009) in Article 1(c) includes ‘harbouring’ in its definition of aggression. But the drafting here is not clear.

40  Corten and Dubuisson, ‘Operation Liberté Immuable: une extension abusive du concept de légitime défense’, 106 RGDIP (2002) 51; Myjer and White, ‘The Twin Towers Attack: an Unlimited Right to Self-defence’, 7 JCSL (2002) 5.

41  Byers, ‘Terrorism, the Use of Force and International Law after 11 September,’ 51 ICLQ (2002) 401.

42  SC Res 1193 (1998), 1214 (1998), 1267 (1999), 1333 (2000).

43  ICJ Reports (2004) 136, para 139. See 142 above.

44  See 142 above.

45  See 216 below on Gaza conflicts.

46  2005 ICJ Reports 168 at para 147. See Okowa, ‘Congo’s War’, 77 BYIL (2006) 203.

47  Insofar as their arguments are based on policy considerations they bear the heavy burden of establishing that widening the permissible use of force would be effective in the ‘war on terror’. See Gray, ‘The limits of force’, 376 Hague Recueil des Cours (2014) 101 at 150.

48  For early discussion, see Becker, Terrorism and the State (2006); Jinks, ‘State responsibility for the acts of private armed groups’, 4 Chicago JIL (2003) 83; Kammerhofer, ‘The Armed Activities case and non-state actors in self-defence law’, 20 Leiden JIL (2007) 89; Murphy, ‘Terrorism and the concept of armed attack in Article 51 of the UN Charter’, 43 Harvard JIL (2002) 41; Ruys and Verhoeven, ‘Attacks by private actors and the right of self-defence’, 10 JCSL (2005) 289; Tams, ‘Note Analytique: swimming with the tide or seeking to stem it’, 18 Revue quebecoise de droit int (2005) 275; Travalio and Altenburg, ‘Terrorism, State responsibility and the use of military force’, 4 Chicago JIL (2003) 97.

49  For a more recent list of those supporting such a doctrine, see Paust, ‘Self-defense targetings of non-state actors and permissibility of US use of drones in Pakistan’, 8 Albany Government Law Review (2015) 163 at note 16.

50  See 237 below.

51  See the attempts by Tsagourias, ‘Self-defence against non-state actors’, 29 Leiden JIL (2016) 801 and Trapp, ‘Actor-pluralism, the turn to responsibility and the Jus ad bellum’, 2016 Journal on the Use of Force and International Law 1, to address this issue in order to support the unwilling or unable doctrine.

52  See 218 below.

53  UN docs S/2003/806, S/2003/758, S/2003/96, S/2002/373, S/2002/986; 2001 UNYB 448. 2002 UNYB 473, 2003 UNYB 516, 2004 UNYB 505.

54  UN doc S/2003/96.

55  UN docs S/2002/135, S/2002/1038, S/2003/148,

56  2001 UNYB 448, UN docs S/PV 4506, 4510 (2002).

57  UN docs S/2002/135, S/2002/1038, S/2003/148. Syria also maintained this position, UN docs S/2001/438, S/2003/178. The UN SC had repeatedly expressed its recognition of the Blue Line as valid for the purpose of confirming Israel’s withdrawal; it had expressed concern at the persistence of tension and violence along the Blue Line and condemned all such acts of violence, including both Hezbollah’s firing of rockets and Israel’s air incursions: SC Res 1583 (2005), 1614 (2005), 1655 (2006). The Secretary-General said that the Blue Line had been drawn by the United Nations and recognized by the Security Council as confirming the withdrawal of Israeli forces from southern Lebanon under Resolution 425 (1978).The Shab’a farms area lay in an area occupied by Israel in 1967 and was therefore subject to a negotiated settlement, Report of the Secretary-General, UN doc S/2002/746. This issue has not been resolved in 2016 and remains a source of tension, UN doc S/2016/931, paras 7, 22, 46.

58  Israel attacked Syrian positions in Lebanon in April and July 2001. It said that Syria was the main power broker in Lebanon with 30,000 troops there, that it supported Hezbollah and allowed it to maintain terrorist training facilities in the Syrian-controlled Bekaa valley. Israel claimed that it was acting in self-defence against Hezbollah attacks on Israeli forces on the Israeli side of Blue Line (2000 UNYB 472, 2001 UNYB 448).

59  UN doc S/PV 4828 (2003); Keesing’s (2003) 45673.

60  UN Press Release SG/SM/8918, 6 October 2003.

61  UN doc S/PV 4836 (2003).

62  Israel has subsequently carried out a series of attacks on non-state actors in Syria, but has not acknowledged responsibility for these attacks or claimed a right of self-defence. In September 2007 it carried out an air raid on an unknown target in Syria. There was speculation that the target was nuclear technology from North Korea, although Syria denied these accusations and they were not substantiated. There was also speculation that Israel had carried out the raid as a warning to Iran, in order to deter it from developing nuclear weapons. Syria protested to the Security Council, but the UN took no action, Keesing’s (2007) 48164, 48224; Syria’s letter to the UN, UN doc S/2007/537. See Gray, ‘The use of force to prevent the proliferation of nuclear weapons’, 52 Japanese YIL (2009) 101. Israel has also attacked (allegedly) Hezbollah-related targets in Syria during the 2011–16 Syrian conflict (Keesing’s (2012) 52353, (2013) 52466, 52699, (2014) 53263, 53767, (2015) 53825); see also Syria’s protest in December 2014 (UN doc S/2014/874), and condemnation by the NAM (UN doc S/2014/573 para 393) and by the Arab League (Keesing’s (2013) 52466). Israel has also carried out a series of attacks on (allegedly) Hamas-related targets in Sudan (Keesing’s (2009) 49073; (2011) 50384; (2012) 52254); see also Sudan’s protest, (UN doc S/2012/790). Israel has not acknowledged its responsibility for these attacks or provided a legal justification. That is, it is not willing to claim openly that this use of force amounts to self-defence.

63  See Secretary-General’s Reports, UN docs S/2006/560, S/2007/392, for an account of the outbreak of the conflict.

64  UN doc SG/SM/10563, 12 July 2006.

65  UN doc S/2006/515, 12 July 2006.

66  UN Press Releases, Humanitarian Fact sheets on Lebanon, IHA/1215, 11 August 2006; IHA/1216, 14 August 2006.

67  UN doc S/PV 5511 (2006).

68  UN doc S/2006/515.

69  UN docs S/PV 5489 (2006); S/PV 5493 (2006).

70  UN doc S/PV 5489 (2006).

71  UN Press Release SC/8781, 20 July 2006.

72  This was the position of Qatar, UN doc S/PV 5489, and of many Arab states, UN doc S/PV 5493 (2006).

73  Report of the Secretary-General UN doc S/2006/560.

74  In many regards the 2006 conflict mirrors that of 1982 when a terrorist attack on the Israeli ambassador in London triggered a massive invasion, the siege of Beirut and the occupation of southern Lebanon for nearly twenty years. In that case there was limited international support for Israel; its invasion and prolonged occupation were seen as clearly disproportionate (1982 UNYB 428–97).

75  UN doc S/2006/515. Similarly, in 2015–16 Israel said that it held Lebanon responsible for attacks by Hezbollah from its territory in its letters to the Security Council justifying its use of force against Lebanon, UN docs S/2015/1003, S/2016/4. Lebanon rejected Israel’s claim to self-defence, UN doc S/PV 7610 (2016) 32. See also Report of the Secretary-General, UN doc S/2016/189, paras 2, 8–10.

76  UN doc S/2006/529.

77  UN doc S/2006/518; UN doc S/PV 5489 (2006).

78  Syrian forces had been present in Lebanon at the invitation of the government since the civil war of 1975–6. From 2004 the USA and France exerted strong pressure on Syria to secure its withdrawal; they secured the adoption of SC Resolution 1559 (2004) calling for the withdrawal of all foreign forces and the disbanding of all militias (see Chapter 3). Elections held in 2005 produced a coalition government of national unity, including two members of Hezbollah: Keesing’s (2005) 46759. Hezbollah remains in the government today.

79  UN doc S/PV 5489 (2006).

80  Lebanon called for an immediate ceasefire in UN docs S/PV 5489 (2006), S/2006/500. The Secretary-General also called for a ceasefire in UN Press Releases SC/8781, 20 July 2006, SC/8790, 30 July 2006.

81  The NAM has condemned the Israeli action as aggression, UN doc S/2014/573, para 299.

82  UN docs S/2006/548, S/2006/569.

83  US and UK speeches, UN doc S/PV 5493 (2006); Speech by PM Tony Blair, 18 July 2006, <http://webarchive.nationalarchives.gov.uk/20080909043937/http://www.number10.gov.uk/Page9870>.

84  SC Res 1697 (2006).

85  UN doc S/PV 5511 (2006).

86  Hamas is categorized as a terrorist organization by the USA, the EU, and many other states. It was founded in 1987 in Gaza. It was elected to govern Gaza in 2006, and in 2007 it seized full control over Gaza from the Fatah-controlled Palestinian Authority.

87  UN doc S/PV 6061 (2009) 6.

88  On the question of occupation, see Human Rights Council, UN doc A/HRC/RES/S-9/1 (2009); HRC Special Rapporteur, UN doc A/HRC/7/17 (2008); UN docs S/PV 6060, 6061. This was also the position of the UN Fact-Finding Mission on the Gaza conflict (the Goldstone Report), UN doc A/HRC/12/48 (2009), and of the Amnesty Report, The Conflict in Gaza (2009). See Bashi and Mann, Disengaged Occupiers: the Legal Status of Gaza (2007). For the UK position, see UK Materials on International Law 81 BYIL (2010) 753; 83 BYIL (2012) 648; 85 BYIL (2014) 670.

89  The same issue of the appropriate legal framework arose with regard to Israel’s use of force against the Turkish flotilla attempting to deliver humanitarian aid in breach of the blockade in 2010. See UN docs S/PV 6325, 6326; 2010 UNYB 439.

90  James, ‘Mere words: the enemy entity designation’, 32 (2009) Hastings Int. Comp. L. Rev 643.

91  UN docs S/2008/807, S/2008/814, S/2008/816. See also UN doc S/2010/21.

92  UN doc S/2008/816. See response by Permanent Observer of Palestine to the UN, UN doc S/2008/819, and Jordan, UN doc S/2008/818.

93  1,800,000 people live in 360 square kilometres of land. In 2014 Luxembourg referred to Gaza as an open-air prison that was becoming a graveyard, UN doc S/PV 7222 (2014) 9.

94  UN doc S/2012/826. See also the letters by Egypt and Palestine, UN docs S/2012/829 and S/2012/840. The SC did not discuss the conflict in public.

95  See briefings to the UNSC, UN docs S/PV 7232, 7243 (2014).

96  UN doc S/PV 7214 (2014).

97  UN doc S/2014/474 referred only to Israel’s responsibility to protect its citizens. Israel also referred to the kidnap and murder of 3 Israeli teenagers as a catalyst; it said that ‘those who target Israelis with terrorism today will pay a very high price tomorrow’, UN docs S/2014/416, S/2014/454. Palestine accordingly rejected Israel’s claims of self-defence on the basis that it was carrying out reprisals and collective punishment, UN doc S/PV7214 (2014) 5. Other factors helping to explain Israel’s decision to take large-scale military action in Gaza in 2014 were the formation of a unity Palestinian government including Hamas and Fatah (welcomed by the UN Secretary-General in Press Release SG/SM/15900, 3 June 2014, but rejected by Israel), and the acceptance of Palestine as a non-member observer state in the UN.

98  It said that it had launched a self-defence operation, to counter the attacks and to defend its citizens, UN doc S/PV 7214 (2014) 5.

99  South Africa, Viet Nam, UN doc S/PV 6060 (2008), Croatia, UN doc S/PV 6061 (2009) 18.

100  UN doc S/2009/36.

101  UN doc S/PV 6061 (2009).

102  UN docs S/PV 7214, 7220, 7222 (2014).

103  See, for example, Jordan, Egypt, Saudi Arabia for the OIC, Pakistan, Morocco, Malaysia, Algeria, Namibia, Ecuador, Turkey, Bolivia for the NAM, and others, UN doc S/PV 7222 (2014).

104  See 294 below.

105  Report of the Secretary-General, UN doc S/2007/381, para 34.

106  2004 UNYB 256.

107  Ibid at 261; SC Res 1587 (2005), 1676 (2006).

108  Keesing’s (2006) 47444.

109  Ibid. In the SC debate on 6 December 2006 John Bolton, the US representative, said that the UIC had sought to destabilize the Horn of Africa region through irredentist claims on the Somali-populated regions of neighbouring states and support for insurgent groups in Ethiopia, UN doc S/PV 5579 (2006).

110  SC Res 1630 (2005), 1676 (2006), 1724 (2006).

111  Reports of Monitoring Group on Somalia, UN docs S/2005/153, S/2005/625, S/2006/229; Reports of the Secretary-General, UN docs S/2005/392, S/2006/838; Report of the Security Council Committee under Resolution 751 (1992), UN doc S/2006/913 at paras 56–86; 15–55; 129–31, 204. The reports also made accusations that other states—Djibouti, Egypt, Iran, Libya, Saudi Arabia, and Syria—supported the UIC. See also UN doc S/PV 5614 (2006), Report of the Secretary-General’s Special Representative.

112  Report of the Secretary-General, UN doc S/2006/838, paras 2, 28

113  Ibid, paras 4–5; Keesing’s (2006) 47296, 47353, 47444, 47398, 47503, 47562. There is a history of bad relations and armed conflict between Somalia and Ethiopia dating back to Somalia’s independence in 1960.

114  UN doc S/PV 5579 (2006).

115  Report of the Secretary-General, UN doc S/2007/115, para 4.

116  UN doc S/PV 5614 (2006); Report of the Secretary-General, UN doc S/2007/115, Keesing’s (2006) 47620.

117  Ibid. See also Keesing’s (2006) 47620, 2006 UNYB 301, Report of the Secretary-General, UN doc S/2007/115.

118  See 129 above.

119  UN doc S/PV 5614 (2006).

120  The Guardian, 9 January 2007.

121  Although there was no official AU statement.

123  Keesing’s (2006) 47296.

124  The USA blamed Eritrea for the violence and said that the insurgency was part of a global jihadist network, Keesing’s (2007) 47852, 48121.

125  Keesing’s (2007) 47735. The USA had provided military aid to Ethiopia since 2002; the two states shared intelligence and the USA provided arms, aid, and training. The USA also intervened directly after the main conflict was over. It carried out a series of targeted killings against suspected terrorists linked with Al Qaida, including those allegedly involved in the 1998 terrorist attacks on the US embassies in Kenya and Tanzania, Report of the Secretary General, UN doc S/2007/115, paras 6, 10; Keesing’s (2007) 47672, 47735. The US targeted killings continued after that date.

126  Report of the Secretary-General, UN doc S/2007/115; Keesing’s (2007) 47672.

127  UN doc S/2007/34; Report of the Secretary-General, UN doc S/2007/204, para 32. On AMISOM, see 397 below.

128  Report of the Secretary-General, UN doc S/2007/115, paras 7–13.

129  For an account broadly sympathetic to Ethiopia, see Yihdego, ‘Ethiopia’s Military Action against the Union of Islamic Courts and others in Somalia’, 56 ICLQ (2007) 666; see also, Corten, ‘La licéité douteuse de l’action militaire de l’Ethiopie en Somalia’, 111 RGDIP (2007) 513.

130  Cf. Armed Activities on the Territory of the Congo, DRC v Uganda, ICJ Reports (2005) 168, para 147.

131  Press Conference by Prime Minster, 28 June 2007, <www.un.org/News/briefings/docs/2007/070628_Somalia.doc.htm>

132  UN doc S/PRST/2006/59.

133  UN doc S/PV 5633 (2007).

134  Similarly the Security Council did not call for an end to the fighting in the 2006 conflict in Lebanon. In this case and that of Somalia—both seen by some as part of a ‘war on terror’—the USA and the UK were unwilling to allow the Security Council to make any such call (US and UK speeches, UN doc S/PV 5493 (2006)).

135  Assembly/AU/Dec.142(VIII), Decisions and Declarations, 29–30 Jan 2007.

136  But there were reports of its continuing intervention, as for example in support of the 2011 Kenyan operation discussed below. See Keesing’s (2011) 50748; Gettleman, ‘Ethiopian Troops said to enter Somalia’, International New York Times, 20 November 2011; Report of the Secretary-General UN doc S/2012/74, para 8.

137  2009 UNYB 270; SC Res 2036 (2012).

139  On recent clashes between AlShaabab and Ethiopian troops, see Report of Secretary-General, UN doc S/2017/21, para 9.

140  This was Kenya’s first cross-border military operation since independence in 1963. See Keesing’s (2011) 50688, 50748; Birkett, ‘The legality of the 2011 Kenyan invasion of Somalia and its implications for ius ad bellum’, 18 JCSL (2013) 427 takes a wide view of the right of self-defence in this case.

141  Kenyan troops were incorporated into AMISOM in February 2012, following SC Res 2036 (2012), 2124 (2013). It is not clear whether subsequent Kenyan military actions in response to a terrorist attack on the Westgate shopping mall in Nairobi (2013), and the massacre at Garissa University (2015) were carried out as part of AMISOM’s mandate under Chapter VII to reduce the threat posed by AlShabaab. Kenya did not report these operations to the Security Council under Article 51. Reports of the Secretary-General, UN docs S/2013/709; S/2016/763, para 15.

142  UN doc S/2011/646; Report of the Secretary General, UN doc S/2011/759, paras 4–5.

143  The AU and IGAD supported the Kenyan operation, UN Secretary-General’s Report, UN doc S/2011/759, para 5.

144  See 149 above.

145  UN doc S/2015/563.

146  UN doc S/2017/350.

147  Turkey claims that the YPG (a Syrian Kurdish group) and the PKK are the same, UN doc S/2016/163.

148  Keesing’s (2015) 54163, 54276, 54329, 54402.

149  See, for example, UN docs S/2016/870, S/2017/410.

150  UN docs S/PV 7589 (2015), S/PV 7623 (2016); S/PV 7689 (2016); S/PV 7804 (2016). See also Reports of Secretary-General, UN docs S/2016/77, paras 26–32; S/2016/897, paras 23–4.

151  UN doc S/2015/963, 2. See also UN docs S/2016/870, S/2017/410.

152  UN doc S/PV 7589 (2015). See also UN doc S/2016/973.

153  Iraq denounced the Turkish forces in Camp Bashiqa on Iraq’s territory as aggressive forces of occupation. It acknowledged the historic links between the peoples of Turkey and Iraq, but rejected the claims of Turkish officials that the Iraqi cities of Kirkuk and Mosul were once Turkish cities. ‘The Security Council must firmly counter these expansionist expressions of greed against a State that is a founding member of the UN and a country with full sovereignty.’ UN doc S/PV 7804 (2016) at 5. See also Turkey’s response, UN doc S/2016/973.

154  Reports of Secretary-General, UN docs S/2016/77, para 32; S/2016/897, para 23.

155  UN doc S/2016/897, para 81. See also UN doc S/PV 7804 (2016) for the continuing protest by Iraq at Turkey’s failure to withdraw its troops.

156  UN doc S/2017/410.

157  2008 UNYB 348.

158  UN doc S/2008/146.

159  OAS documents, OAS/CP/RES/930 (1632/08), 5 March 2008; RC.25/RES.1/08, 17 March 2008. The USA rejected the statement in the latter resolution that declared that the Colombian incursion violated Articles 19 and 20 OAS Charter.

160  Keesing’s (2008) 48456.

161  Keesing’s (2002) 44630, 44662, 44686, 44747, 44810, 44951, 44998, 45050.

162  UN doc S/2002/1012. For Georgia’s reply see UN doc S/2002/1033. Georgia accused Russia of violations of its sovereignty by bombers and military helicopters and spoke of the ‘Unaptness’ of the reference by Russia which allows an attacked state to render armed resistance in order to defend its territorial integrity and sovereignty. Russia had not been subjected to armed aggression by Georgia. Repeated attempts are being made to blame Georgia for its inability to provide security for Russia on the Chechen segment of the Georgian–Russian state border, where the current situation has been deliberately created by the Russian Federation itself.

163  ‘Monitors confirm Russian attack on Georgia’, Paton Walsh, The Guardian, 24 Aug 2002, 16; ‘US rebukes Russia for Pankrisi raid’, Paton Walsh, The Guardian, 26 Aug 2002, 12.

164  Keesing’s (2002) 44630, 44686, 44749, 44951.

165  See discussion by Tsagourias, note 51 above, and by Corten, Le droit contre la guerre (2nd edn 2015) at Chapter III, for a doctrinal argument that there can be no armed attack by a non-state actor, because the prohibition on the use of force applies only to states.

166  See, for example, Simma, Khan, Nolte, and Paulus (eds), The UN Charter: a Commentary (3rd edn 2012) at 1418.

167  Trapp, note 51 above, and Trapp, ‘Can non-state actors mount an armed attack?’, in Weller (ed), Oxford Handbook on the Use of Force in International Law (2015), 679.

168  See 237 below.

169  See the contrasting positions of Kretzmer, ‘The inherent right to self-defence and proportionality in ius ad bellum’, 24 EJIL (2013) 235 and Nolte, ‘Multi-purpose self-defence, proportionality disoriented’, 24 EJIL (2013) 283.

170  UK AG’s Speech in the House of Lords, HL Debates 21 April 2004, Vol 660, c369–72; UK Materials in International Law, 75 BYIL (2004) 822–3; US State Department Legal Adviser, Taft, ‘Self-Defense and the Oil Platforms decision’, 29 Yale JIL (2004) 295.

171  UN doc S/PV 5493 (2006).

172  UN doc S/PV 5498 (2006); see also UN doc S/PV 5511 (2006).

173  UN docs S/PV 5493, S/PV 5498, S/PV 5511 (2006).

174  This was the position of the UK, Denmark and Greece.

175  UN doc S/PV 5493 (2006).

176  UN doc S/2006/515.

177  UN doc S/PV 5511 (2006).

178  UN doc S/PV 5493 (2006) at 4–5.

179  Ibid at 8.

180  Ibid at 16; UN doc S/PV 5493 Res. 1 at 5.

182  2006 Havana Conference, Final Declaration, UN doc S/2006/780, at paras 142–3; UN doc S/PV 5629 (2007). See also UN doc S/2014/573, para 299. The Organization of the Islamic Conference also expressed strong condemnation of Israeli aggression, UN doc S/2006/959.

183  Israel said that ‘Thus a clear distinction is made between the two parties to the military hostilities, and Israel is given permission by the Security Council to continue defensive actions against a terrorist organization.’ (Israeli Ministry of Foreign Affairs, ‘Behind the Headlines: UN Security Council Resolution 1701’, 12 August 2006.)

184  The Arab League expressed concern during negotiations, UN doc S/PV 5508 (2006); Lebanon also expressed dissatisfaction with Resolution 1701, UN doc S/PV 5511 (2006). See also the letter from Qatar to the Security Council, UN doc S/2006/655.

185  See the series of Reports of the Secretary-General in the immediate aftermath of the conflict, UN docs S/2006/670, S/2006/780, S/2006/933, S/2006/730, S/2007/147, S/2007/641. Subsequent reports also find continuing violations of Resolution 1701 (2006) by Israel and Hezbollah. Israel continually violates Lebanon’s airspace, despite protests from Lebanon and UNIFIL, and it illegally occupies part of the Ghajar village in Lebanon; Hezbollah maintains a substantial military capacity in Lebanon separate from that of the Lebanese state. The reports have also condemned both Israel and Hezbollah after incidents in 2013–16. See UN docs S/2013/650, S/2014/784, S/2015/147, S/2016/189.

186  See the Reports of the Secretary-General on the implementation of SC Resolution 1701 (2006). There were fears that the sectarian conflict in Syria would spill over into Lebanon with its complex mix of different religious communities. Moreover, Hezbollah was engaged in the conflict in Syria on the side of the Assad government.

187  On the events leading up to the 2008–9 conflict, see 2008 UNYB 489. On the outbreak of the 2012 and 2014 conflicts, see Keesing’s (2012) 51017, 52088, 52351; (2014) 53532.

188  For a statement of this position, see speeches by the Palestine, the Arab League and Qatar, UN doc S/PV 6061 (2009) 5, 24, 34. See also statements by a wider range of states in response to the 2014 conflict, UN doc S/PV 7222 (2014); and more recently UN doc S/PV 7772 (2016).

189  In 2008–9 over 1,400 Palestinians and 13 Israelis were killed; in 2014 over 1,800 Palestinians (including over 500 children) and 73 Israelis.

190  For example, Turkey, Austria Vietnam, Mexico, Malaysia, Brazil, Argentina, Pakistan, Iceland, Ecuador, Bolivia, Paraguay, UN doc S/PV 6061 (2009). The UN Secretary-General also took this position in 2008–9, UN docs S/PV 6060 (2008), 6061 (2009); Press Release SG/SM/12036, 5 Jan 2009. Again in 2014 the majority of states regarded Israel’s fifty-day campaign as disproportionate, UN doc S/PV 7222 (2014). The USA and the UK did not join in the condemnation, but they did express concern about the civilian casualties.

191  The General Assembly passed a resolution demanding respect for SC Res 1860 by 143–3 (USA, Israel, Nauru) with nine abstentions, UN doc A/ES-10/L.21/Rev.1.

192  UK Foreign Affairs Committee Report HC 196, para 76; Report HC 384, para 87.

193  Keesing’s (2002) 45142.

194  See, for example, Keesing’s (2002) 44724, (2006) 47520, (2006) 47467, (2007) 47694, 47695, 47755. The USA has carried out a series of drone attacks on Al Qaida and Taliban suspects inside Pakistan, see 233 below on targeted killing. In May 2011 it carried out a lethal operation against Osama bin Laden, the founder of Al Qaida, 105 AJIL (2011) 602.

195  ISAF was authorized by the Bonn Agreement of December 2001 and endorsed by UN SC Res 1386 under Chapter VII, 42 ILM (2002) 1032. It was initially 5,000 strong and was gradually expanded until it reached a peak of 130,000. Some expressed doubts as to the compatibility of ISAF and Operation Enduring Freedom. ISAF terminated at the end of 2014. <www.nato.int/cps/en/natohq/topics_69366.htm>.

196  Keesing’s (2003) 45403.

197  Keesing’s (2014) 53743.

198  Report of the Secretary-General, UN doc S/2016/1049, paras 15–22. See also Report of the Secretary-General UN doc S/2017/508 which said that the situation remained ‘intensely volatile’, and the briefing in UN doc S/PV 7980 (2017).

199  From SC Res 1589 (2005) to SC Res 2274 (2016). SC Res 2344 (2017) also expressed concern at the presence of ISIS in Afghanistan.

200  Murphy, ‘Contemporary Practice of the United States relating to International Law’, 97 AJIL (2003) 419 at 428; Keesing’s (2003) 45315.

201  These resolutions continued until SC Res 2096 (2013).

202  See, for example, 2006 US National Security Strategy 12 (available on White House website <www.whitehouse.gov/>).

203  Military occupation, and the deaths of civilians caused by US air attacks aimed at Al Qaida and insurgent forces inevitably led to new recruits for those opposed to the US presence. If the ‘war on terror’ is to continue until the threat of terrorism is defeated then it is difficult to see an end. President George W Bush spoke of the ‘war on terror’ as an inter-generational war in his 2007 State of the Nation Address, Keesing’s (2007) 47683, and similar language has been used more recently with regard to the threat posed by ISIS, see 237 below.

204  Security and Defense Cooperation Agreement between Afghanistan and the USA, 54 ILM (2015) 272.

205  Report on Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations, 5 Dec 2016, at 15. President Trump has announced an increase in the number of US troops and continuing engagement in Afghanistan, Hirschfeld Davis and Landler, ‘Trump outlines new Afghanistan war strategy with few details’, New York Times, 21 August 2017, <www.nytimes.com/2017/08/21/world/asia/afghanistan-troops-trump.html>.

206  See Gray, note 47 above.

207  This term came into general use during the 2000 Palestinian uprising against Israeli occupation of the West Bank and Gaza when Israel made public its policy of killing alleged terrorists in the Occupied Palestinian Territories. ‘Targeted killing’ is generally understood to mean ‘premeditated acts of lethal force to eliminate specific individuals outside their custody’, UN Special Rapporteur Philip Alston, Study on Targeted Killing, UN doc A/HRC/14/24/Add.6 (28 May 2010). In practice, US drone attacks have also involved ‘signature attacks’ on groups of unidentified individuals on the basis of their behaviour. The USA and Israel are the only states openly to acknowledge a policy of targeted killings outside a ‘hot battlefield’.

208  The USA’s domestic legal basis for the use of force is still the AUMF passed after 9/11 (see 207 above). This Congressional authorization of force has been widely interpreted by the Obama administration to cover military actions against organizations affiliated to Al Qaida around the world, including operations against ISIS in Iraq, Syria, and Libya (despite the 2014 split between Al Qaida and ISIS). See 109 AJIL (2015) 207; 110 AJIL (2016) 810. See also the Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations, 5 Dec 2016, and Agora on the AUMF, 110 AJIL (2016) 625.

210  President George W Bush had initiated the US targeted killings programme after the 9/11 attacks. See Melzer, Targeted Killing in International Law (2008); O’Connell, ‘The choice of law against terrorism’, 4 J Nat Sec Law and Policy (2010) 343; Martin, ‘Going Medieval: Targeted killing, self-defense and the ius ad bellum regime’, in Finkelstein, Ohlin, and Altman (eds), Targeted Killings (2012) 223; Heyns, Akande, Hill-Cawthorne, and Chengeta, ‘The international legal framework regulating the use of armed drones’, 65 ICLQ (2016)791.

211  For a complete list, see the White House Report on Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations, 5 Dec 2016, Appendix, <https://obamawhitehouse.archives.gov/sites/whitehouse.gov/files/documents/Legal_Policy_Report.pdf>. See Gray, ‘Targeted killings: recent US attempts to create a legal framework’, 66 Current Legal Problems (2013) 75.

212  Israel makes a similar claim that it is fighting an ongoing armed conflict with Hamas and other groups in order to justify its targeted killings in Gaza and elsewhere. See the Israeli Supreme Court decision in The Public Committee against Torture in Israel v the Government of Israel, 45 ILM (2007) 375. For a defence of the Israeli policy, see Blum and Heymann, ‘Law and policy of targeted killing’, Harvard National Security Journal (2010) 145. The UK position was that it would not carry out targeted killings outside an area of active hostilities, but it carried out a controversial operation in Syria in August 2015 (before it joined the US-led coalition in operations in Syria) on the basis that the target was planning and directing imminent armed attacks against the UK (UN doc S/2015/688; Syrian response UN doc S/2015/719); see ‘Op-Eds on Joint Committee’s Drones Report’, 3 Journal on the Use of Force and International Law (2016) 198.

213  For a recent statement of this position, see the speech by Brian Egan, US State Department Legal Adviser <https://www.justsecurity.org/wp-content/uploads/2016/04/Egan-ASIL-speech.pdf>, at 6, and the White House Report on Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations, 5 Dec 2016.

214  The UK AG in a major speech on the scope of self-defence at the start of 2017 said, ‘I am certainly not suggesting we adopt an analysis which amounts to a Global War on Terror paradigm’,  <www.gov.uk/government/speeches/attorney-generals-speech-at-the-international-institute-for-strategic-studies>.

215  Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations, 5 Dec 2016, 4–7. See Ingber, ‘Co-Belligerency’, 42 Yale JIL (2017) 67.

216  The US policy allows the killing of those suspected of planning attacks on the USA. Much of the criticism of the US targeting killing policy, and especially of the role of the CIA in carrying out targeted killing, focused on the lack of transparency: see Alston note 210 above. In May 2013 President Obama issued a Presidential Policy Guidance on strikes outside areas of active hostilities, and this was published in an edited form in August 2016: <https://www.justice.gov/oip/foia-library/procedures_for_approving_direct_action_against_terrorist_targets/download>.

In September 2017 there were media reports that President Trump proposed to relax these guidelines, <https://www.nytimes.com/2017/09/21/us/politics/trump-drone-strikes-commando-raids-rules.html>.

217  See Gray, note 211 above at 102.

218  This wide view had been put forward by Yoo, ‘Using Force’, 71 UChiLR (2004) 729; Bethlehem, ‘Self-defense against imminent or actual armed attack by non-state actors’, 106 AJIL (2012) 769. See replies by Glennon, ‘Law, Power and Principles’, 107 AJIL (2013) 378; O’Connell, ‘Dangerous Departures’, ibid 380; Wilmshurst and Wood, ‘Reflections on the Bethlehem Principles’, ibid 390; Tladi, ‘An assessment of Bethlehem’s principles on the use of force against non-state actors without the consent of the innocent territorial state’, ibid 570. The UK AG subsequently adopted the Bethlehem principles in his 2017 speech, note 214 above.

220  See note 213 above. See also the White House Report on Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations, 5 Dec 2016.

221  See critical comments by UN HRC Special Rapporteur Christof Heyns, UN doc A/68/382 (2013), paras 85–94; and also Lubell, ‘The problems with imminence in an uncertain world’, in Weller (ed), Oxford Handbook on the Use of Force in International Law (2015), 697.

224  UN doc S/2014/691.

225  UN doc S/2014/695.

226  In Syria the USA has carried out targeted killings of several suspected of planning external terrorist operations, including those allegedly involved in the 2015 terrorist attacks on Paris, or in planning future attacks on targets outside Syria: see <https://www.defense.gov/News/Special-Reports/0814_Inherent-Resolve>;  <http://www.longwarjournal.org/tags/islamic-state-external-attack-planners>.

227  See, for example, the Netherlands’ position set out in an ‘Article 100 Letter on Participation in the International Fight against ISIS’, 24 Sept 2014, Reference: DVB/CV-178/2014, <www.rijksoverheid.nl/documenten-en-publicaties/kamerstukken/2014/09/24/artikel-100-brief-deelneming-aan-internationale-strijd-tegen-isis.html>; see also Corten, ‘The unwilling or unable test’, 29 Leiden JIL (2016) 772 at 781.

228  Saudi Arabia, Jordan, Bahrain, UAE (Keesing’s (2014) 53593.

229  UN doc S/PV 7316 (2014) 33.

230  UN doc S/2015/221.

231  UN doc S/2015/693.

232  UN doc S/2015/745.

233  UN doc S/2015/563. Turkey had earlier carried out an operation of very doubtful legality in Syria, to relocate the Suleyman Shah shrine from Syria to Turkey, Keesing’s (2015) 53882. It claimed that this was part of Turkish territory and that it was acting in self-defence against an imminent attack by ISIS, UN doc S/2015/127. Turkey later took action in Syria, without Syria’s consent, against Syrian Kurds who were supported by the USA in the fight against ISIS, UN docs S/2016/45, S/2016/101, S/2016/147, S/2016/149 (Syria); S/2016/163 (Turkey).

234  UN doc S/2015/574.

235  UN doc S/PV 7565 (2015) 2. The USA, UK, Canada, and Turkey also claimed individual self-defence against attacks by ISIS and Al Qaida originating in Syria, as well as collective self-defence; the other states taking part in the air strikes claimed only collective self-defence.

236  Alabrune, ‘Fondements juridiques d’intervention militaire française contre Daech’, 41 RGDIP (2016) 41; Latty. ‘Le brouillage des repères du ius contra bellum’, 120 RGDIP (2016) 11.

237  This raises the crucial, but sensitive, issue of how to determine gravity in this context.

238  UN doc S/2015/928.

239  UN doc S/2015/946.

240  UN doc S/2016/523.

241  UN docs S/2016/34, S/2016/132, S/2016/513.

242  UN doc S/2015/719. See also UN doc S/2015/1048; UN doc S/PV 7527, 29–30.

243  UN doc S/PV 7271.

244  In its letter to the Security Council the USA said that ‘the Syrian regime has shown that it cannot and will not confront these safe havens effectively itself’. Subsequently, the USA has said only that Syria was ‘unwilling or unable’ to prevent the use of its territory for attacks by ISIS, without specifying whether Syria was both unwilling and unable. UN doc S/2014/695. See also the White House Report on Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations, 10, and Egan note 213 above at 7.

245  UN doc S/2015/789. States hostile to the Syrian government claimed that it had not acted against ISIS, but instead had taken action against the ‘moderate opposition’, UN doc S/PV 7527 (2015), at 22 (USA), 23 (UK), 37 (Turkey); UN doc S/2015/693 (Australia), and reply by Syria UN docs S/2015/719, 727, 873.

246  Note 236 above at 44.

247  See Chapter 3.

248  See ‘Self-defence against non-state actors: impulses from the Max Planck Trialogues on the Law of Peace and War’, 77 Zeitschrift für ausländisches öffentliches Recht und Völlkerrecht (2017). Olivier Corten makes the thorough-going doctrinal case that the Charter regime does not regulate the use of force by non-state actors. He argues that non-state actors cannot carry out armed attacks in the absence of state involvement, and that therefore it is not appropriate to say there is a right of self-defence against them. Attacks on non-state actors in third states necessarily violate Article 2(4) in the absence of host state consent. Corten, Le droit contre la guerre (2nd edn 2015) at Chapter III; Corten, note 227 above at 795.

249  See note 213 above at 5. See also, Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations, 5 Dec 2016, at 9. The UK AG does not take this position, note 214 above.

250  UN doc S/2014/573 para 25.

251  The ILC in its Conclusions and commentary on the identification of customary international law, Article X, has suggested that silence might indicate opinio juris. However, the examples given are very different from the use of force, and it is open to question whether the modification of a rule widely regarded as ius cogens could be achieved by the silence of the majority of states. Certain writers claim that silence amounts to acceptance in this context, Trapp ‘Can non-state actors mount an armed attack?’, note 167 above; van Steenberghe, ‘The law against war or Jus contra Bellum’, 24 Leiden JIL (2011) 747.

252  UN doc S/PV 7527 (2015).

253  Foreign Policy Concept (approved by President Putin on 30 Nov 2016), para 32.

254  Ibid, para 26.

255  UN doc S/PV 7565 (2015) 5; see also UN doc S/PV 7271 (2014) 19.

256  UN doc S/PV 7565 (2015) 7.

257  Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations at 10.

258  Deeks has claimed that the ‘unwilling or unable’ doctrine is supported by more than a century of state practice, and she traces it back to the law of neutrality (though that law does not apply to non-international armed conflicts, such as that with ISIS). But the evidence is not persuasive, in that some of the incidents she cites do not involve the use of that language, and where the language is used it is not obvious that it is part of a claim to self-defence: Deeks, ‘ “Unwilling or Unable”: Towards a normative framework for extraterritorial self-defense’, 52 Virg JIL (2012) 483. US SD Legal Adviser Brian Egan did not go so far as to claim that the ‘unwilling or unable’ doctrine is long-established (note 213 above). There was no focused discussion of such a doctrine in the academic literature until the debate began about the legality of targeted killings by the Obama administration. The doctrine was apparently first put forward as a possible basis for the use of force in 2006, 55 ICLQ (2006) 964. Reinold, note 15 above, identified it as an emerging doctrine.

259  Thus, Chacko and Deeks in their useful survey of state practice ‘Who is on board with ‘unwilling or unable’?,<https://www.lawfareblog.com/who-board-unwilling-or-unable>, include state practice under the heading ‘Explicit endorsement’ that does not actually use this language. They also include under the heading ‘Implicit endorsement’ practice that might better have been included under ‘Ambiguous cases’.

260  France, Germany, Belgium, Denmark, Netherlands, Norway.

261  See UK AG’s 2017 speech on self-defence, note 214 above. He did not go into the fundamental question of how to reconcile the use of force against non-state actors with the sovereignty of the host state.

262  UN doc S/2015/963.

263  UN doc S/PV 7804 (2016).

264  UN doc S/2016/16.

265  Deeks, note 258 above.

266  Tzouvala, ‘TWAIL and the unwilling or unable doctrine’, 109 AJIL Unbound (2016).

267  Note 205 above at 10. The UK AG did not accept this approach in his speech on the scope of self-defence, note 214 above.

268  See UN HRC Special Rapporteur Ben Emmerson, Interim Report, UN doc A/68/389 para 55; 110 AJIL (2016) 811; Gray, note 47 above, at 150. Pakistan protested again in June 2017, <https://www.ispr.gov.pk/front/main.asp?o=t-press_release&id=4050&cat=army>.

269  Note 205 above at 11.

270  Some commentators claim that if there is enough state practice in support of the right to use force in self-defence against non-state actors then there is no problem. See Paust, ‘Self-defense targetings of non-state actors and permissibility of US use of drones in Pakistan’, 8 Albany Government Law Review (2015) 163.

271  See Chapter 2.

272  UN docs S/2015/933, S/2015/950, S/2015/1014; S/2016/31.

273  See Chapter 3 at 118.

274  See ‘Self-defence against non-state actors: impulses from the Max Planck Trialogues on the Law of Peace and War’, 77 Zeitschrift für ausländisches öffentliches Recht und Völlkerrecht (2017). Many write in support of the doctrine: Schmitt, ‘Extraterritorial lethal targeting’, 52 Columbia JTL (2013) 77; Hakimi, ‘Defensive force against non-state actors’, 91 Int Legal Studies (2015) 1; van Steenberghe, ‘Self-defence in response to attacks by non-state actors in the light of recent state practice’, 23 Leiden JIL (2010) 183. For a strong rejection of the doctrine, see Corten, notes 248 above, 275 below.

275  Corten, ‘Has state practice led to an agreement between parties regarding the interpretation of Article 51 of the UN Charter?’, in ‘Self-defence against non-state actors: impulses from the Max Planck Trialogues on the Law of Peace and War’, 77 Zeitschrift für ausländisches öffentliches Recht und Völlkerrecht (2017); Brunnée, ‘Self-defence against non-state actors: are powerful and Toope states willing but unable to change the law?’, 67 ICLQ (2018).

276  Tibori-Szabó, ‘The unwilling or unable test and the law of self-defence’, in Paulussen et al. (eds), Fundamental Rights in International and European Law (2016), 73.

277  Tsagourias, note 51 above, examines the different types of argument. He suggests that it is possible to rely on Article 21 of the ILC Articles on Responsibility of States for Internationally Unlawful Acts as a justification for the use of force against non-state actors, but this argument misconceives the role of circumstances precluding wrongfulness. See Christakis and Banelier, ‘Le légitime défense en tant que circonstance excluant l’illicéite’ in Kherad (ed), Légitimes défenses (2007), 254.

278  Trapp, ‘Can non-state actors mount an armed attack?’, note 167 above; Trapp, ‘Actor-pluralism, the turn to responsibility and the Jus ad bellum’, note 51 above. For criticism of this type of argument, see Corten, note 248 above.

279  ICJ Reports (1949) 4 at 12, 35.

280  ICJ Reports (2005) 168 at paras 301–3, 148–65.

281  UN doc S/2001/946; 40 ILM (2001) 1280.

282  UN doc S/2001/947; ‘UK Materials on International Law’, 72 BYIL (2001) at 682.

283  See, for example, Bothe, Terrorism and the Legality of Pre-emptive Force’, 14 EJIL (2003) 227; Glennon, ‘The Fog of Law: Self-defense, inherence and incoherence in Article 51 of the UN Charter’, 25 Harvard Journal of Law and Public Policy (2002) 539; Sofaer, ‘On the need of pre-emption’, 14 EJIL (2003) 209; Farer, ‘Beyond the Charter Frame: Unilateralism or Condominium?’, 96 AJIL (2002) 359; ‘Agora: Future Implications of the Iraq Conflict’, 97 AJIL (2003) 553. Nolte, ‘Preventive use of force and preventive killing’, in Theoretical Inquiries in Law (2004), 111.

284  Available on the US Department of State website <www.state.gov/>.

285  Though some commentators argue that the USA had adopted this wide position much earlier. See, for example, Reisman and Armstrong, ‘The past and future of claims of preemptive self-defence’, 100 AJIL (2006) 525, and discussion by Murphy, ‘The doctrine of preemptive self-defense’, 50 Villanova LR (2005) 699.

286  54 ICLQ (2005) 767, para 3. In contrast the Dutch government interpreted the 2002 US National Security Strategy as allowing force only against imminent threats; it also itself rejected the use of force in pre-emptive action against non-imminent threats: Government letter to the House of Representatives, 29 October 2004, 29800 V, no. 56.

287  High-level Panel Report, UN doc A/59/565, paras 189–92. In Larger Freedom, UN doc A/59/2005, 21 March 2005, para 125, said ‘where the threat is not imminent but merely latent the Charter gives full authority to the Security Council to use military force.’

288  See 253 below.

289  Assistant Secretary of State Kim Holmes, speech of December 2004, 99 AJIL (2005) 494.

290  Available on the White House website.

291  2006 USNSS 9.

292  Ibid, 9, 20.

293  Ibid, 23.

294  Australia was the most outspoken supporter of the US doctrine; in the aftermath of the bomb attack on the Bali night club in December 2002 it asserted a right of pre-emptive self-defence against terrorists in neighbouring states. Early indignation by Indonesia, Malaysia, Philippines, and Thailand, was increased by later suspicion that Australia was really trying to justify future action against Iraq, Keesing’s (2002) 45147. See Ruys, Armed Attack and Article 51 of the UN Charter (2010), 330. However, Australia did not persist with this doctrine, Australian Government, Responding to the Australia 2020 Summit, 255, <www.tda.edu.au/resources/2020_Summit_paper.pdf>.

295  UN Press Releases GA/10377, 10388, 10399, 6–8 April 2005.

296  For example, in the 2006 Havana Declaration, UN doc S/2006/780, 29 September 2006, paras 20, 22.5. See also UN doc S/2014/573 at 28.

297  The EU in its 2003 Security Strategy identified five key threats: terrorism, the proliferation of WMD, regional conflicts, state failure, and organized crime. It goes on to say that with the new threats the first line of defence will often be abroad. But the EU did not expressly adopt the doctrine of pre-emptive self-defence, in marked contrast to the US National Security Strategy.

298  ICJ Reports (2005) 168, para 143.

299  Ibid, para 148.

300  See Gray, ‘President Obama’s 2010 USNSS and international law on the use of force’, 2011 Chinese JIL 35. For the contrary view that Obama actually rejected pre-emptive self-defence, see Henderson, ‘The 2012 USNSS and the Obama doctrine of necessary force’, 15 JCSL (2010) 403.

301  The Foreign Secretary clearly disavowed such a doctrine, Foreign Affairs Committee, Second Report, Foreign Policy Aspects of the War against Terrorism, Session 2002–2003, HC 196 at para 150. See also the UK AG’s advice on the legality of the invasion of Iraq, 54 ICLQ (2005) 767, para 3.

302  UK AG’s speech in the House of Lords, HL Debates, 21 April 2004, Vol 660, c369–72; UK Materials in International Law, 75 BYIL (2004) 822–3. The UK AG reaffirmed this express rejection of pre-emptive self-defence in January 2017, <www.gov.uk/government/speeches/attorney-generals-speech-at-the-international-institute-for-strategic-studies>.

303  UK AG’s speech in the House of Lords, HL Debates, 21 April 2004, Vol 660, c369–72; UK Materials in International Law, 75 BYIL (2004) 822–3.

304  See UK AG’s 2017 speech, note 214 above. Australia also adopted this approach in 2017, see note 222 above.

305  Keesing’s (2002) 44545.

306  See McGoldrick, From 9/11 to Iraq (2004).

307  Keesing’s (2002) 45009, 45029, (2003) 45265, 45546, 45588.

308  UK Foreign Affairs Committee, Seventh Report of Session 2001–02, Foreign Policy Aspects of the War Against Terrorism, HC 384, para 215.

309  See, for example, Keesing’s (2003) 45009.

310  See 367 below on the justification of UN authorization as the basis for the use of force against Iraq.

311  Keesing’s (2002) 45005, 45067, (2003) 45216, 45313. Russia, China and many EU states did not accept the case for the use of force against Iraq. For a statement of the Russian position, see 52 ICLQ (2003) 1059.

312  42 ILM (2003) 244; NATO Press Release (2002) 133, 21 November 2002.

313  41 ILM (2002) 1440.

314  UN docs S/2003/350; S/2003/352. Australia expressly said that there was no need to consider self-defence: Memorandum of Advice on the Use of Force against Iraq provided by the Attorney-General’s department and the Department of Foreign Affairs and Trade, 18 March 2003.

315  The USA claimed that more states were involved in the ‘coalition’ in favour of military action than had been involved in the 1991 operation authorized by the UN. Forty-five states were involved in Operation Iraqi Freedom, Keesing’s (2003) 45315; Murphy, ‘Contemporary Practice of the United States relating to International Law’, 97 AJIL (2003) 419 at 428.

316  See, for example, Yemen and Iran, UN doc S/PV 4625 (2002); Malaysia, Yemen, Vietnam, Iran, and Lebanon, UN doc S/PV 4726 (2003).

317  Keesing’s (2003) 45216, 45264. The UN Secretary-General also expressed doubts over a resort to force rather than the continuation of the work of the weapons inspectors, Keesing’s (2003) 45217. Zacklin, The UN Secretariat and the Use of Force (2010) 135.

318  See The Report of the Iraq Inquiry (the Chilcot Report) UK HC 264, 6 July 2016, Executive Summary, paras 496–570, 297–339.

319  See the Chilcot Report, Executive Summary.

320  Ibid, paras 571–89; Keesing’s (2004) 46280. The report did suggest that Saddam Hussein intended to restart WMD production when possible, but it did not give any evidence for this.

321  Keesing’s (2003) 45571, 45587, 45623, 45671. See Reports of the Secretary-General UN docs S/2016/92, S/2016/501, S/2017/97, S/2017/467.

322  For an attempt to draw up a framework governing pre-emptive action, see Buchanan and Keohane, ‘The pre-emptive use of force: a cosmopolitan institutional perspective’, 2004 Ethics and International Affairs 1.

323  ‘Agora: Future Implications of the Iraq Conflict’, 97 AJIL (2003) 553; ‘Unilateralism in International Law: A US-European Symposium’, 11 EJIL (2000) 1 at 349.

324  UN Press Release DSG/SM/196, 12 May 2003. The Marshall Islands brought cases against all nuclear weapons states for violation of their obligations of non-proliferation. Only three cases proceeded to the ICJ, and those were not admissible, Obligations concerning negotiations relating to cessation of the nuclear arms race, ICJ Reports (2016).

325  The USA had designated Iran, Iraq, and North Korea as ‘state sponsors of terrorism’. It also included Cuba, Libya, Sudan, and Syria in this category. Today only Iran, Sudan, and Syria remain on the list.

326  UN Press Release GA/DIS/3247, 3 October 2003.

327  Ibid. See also Secretary-General’s Press Release, SG/SM/10527, 21 June 2006. For a discussion of pre-emption and deterrence, see Verdirame, ‘The sinews of peace’, 77 BYIL (2006) 83.

328  Keesing’s (2001) 44545.

329  Keesing’s (1994) 40140, 40227. On the decline in relations between the USA and North Korea, see Keesing’s (2001) 44006, 44055, 44214, (2002) 44619, 44676, 44939, 45088, 45138.

330  SC Res 825 (1993) called on North Korea to reconsider its announcement, to reaffirm its commitment to the NPT and to honour its non-proliferation obligations.

331  Keesing’s (2001) 44104, 44402, (2002) 44619, 44788, (2003) 45407.

332  Keesing’s (2002) 45039, 45138; (2003) 45187. See also UN doc S/2012/680.

333  Keesing’s (2002) 44619, 44676, 45287.

334  Keesing’s (2003) 45238; UN doc S/2003/91.

335  Keesing’s (2003) 45187. See more recently, UN doc S/2015/799, for North Korea’s call for a peace treaty.

336  2006 US National Security Strategy 3, 19, 21.

337  UN doc S/PV 5490 (2006).

338  Keesing’s (2006) 47515.

339  This resolution was carefully drafted so as to exclude any claim that it could be interpreted as authorizing the use of force against North Korea. See Chapter 7.

340  UN doc S/PV 5551 (2006).

341  SC Res 1874 (2009), 2087, 2094 (2013), 2270, 2321 (2016), 2356, 2371, 2375 (2017).

342  For example, in March 2016 it said, ‘As the joint military exercises to be staged by the enemies [the USA and South Korea] are regarded as the most undisguised nuclear war drills aimed to infringe upon the sovereignty of the DPRK, its military counteraction will be a more pre-emptive and offensive nuclear strike to cope with them’, UN docs S/2016/222. See also, UN docs S/2015/373, S/2015/799, S/2016/222, S/2016/549, S/2016/747, S/2016/771, S/2016/1023.

343  UN doc S/2016/988. See recent discussion in UN doc S/PV 7958 (2017) when the USA said that all options remained on the table.

344  See, for example, Keesing’s (2003) 45267, 45320, 45432, 45492.

345  2006 US National Security Strategy 20.

346  Final Document, Havana Conference 2006, UN doc S/2006/780, Annex IV; see also, UN docs S/2006/1018.

347  Keesing’s (2005) 46854, (2006) 47122.

348  Keesing’s (2006) 47230.

349  SC Res 1737 (2006), 1747 (2007), 1803, 1835 (2008), 1887 (2009) 1929 (2010). In the Security Council debates leading up to these resolutions Russia pointed out that the language of the resolutions excluded the use of force, UN docs S/PV 5500, S/PV 5612 (2006), S/PV 5647 (2007). See Chapter 7.

350  Keesing’s (2005) 46494, (2006) 47230, (2007) 47679, 47723, 47780, 48015, 48102, 48163. The UN chief weapons inspector warned against such rhetoric and reminded states of the lessons of Iraq, ‘UN nuclear boss warns warmongers over Iran’, Walker and Tran, The Guardian, 17 September 2007; ‘Russia warns against military action in Iran’, Tran, The Guardian, 18 Oct 2007. Russia also spoke out against the use of force, ‘Putin warns US against military action in Iran’, Tait, The Guardian, 17 October 2007.

351  ‘Defiant Bush says Iran still poses a threat’, MacAskill, The Guardian, 5 Dec 2007. Israel took the same position, ‘Unilateral military action still an option’, McCarthy, The Guardian, 8 December 2007.

352  UN doc S/2006/603.

353  This was also the UK position; it said ‘all options remain on the table’, but did not give any legal basis for the possible use of force. See ‘UK Materials on International Law’, 83 BYIL (2012) 599–602.

354  Keesing’s (2012) 50956, 52353, 52181; UN Press Release, <www.un.org/News/Press/docs/2013/ga11432.doc.htm>. Israel put pressure on the USA to commit to the use of force against Iran if certain ‘red lines’ were crossed, Keesing’s (2012) 52239.

355  UN docs S/2012/372, S/2012/660, S/2015/353, S/2016/279. Iran’s position is that Israel’s statements are in ‘flagrant violation of the most fundamental provisions of the Charter of the UN’. It pointed out that Israel itself is a nuclear weapons power, UN doc S/2012/817.

356  Lindsay, ‘Stuxnet and the limits of cyber warfare’, 22 Journal of Security Studies (2013) 365; Simmons, ‘A brave new world’, 4 Journal of Law and Cyberwarfare (2014) 42; Sanger and Mazzetti, ‘US had cyberattack plan if Iran nuclear dispute led to conflict’, New York Times, 16 Feb 2016.

357  Keesing’s (2012) 50901, 52179.

358  SC Res 2231 (2015). For the most recent SC discussion, see UN doc S/PV 7990 (2017).

359  ‘Interview with Jacques Chirac’, New York Times, 9 Sept 2002.