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Targeted Killing in International Law by Melzer, Nils (10th September 2009)

Part A State Practice and Legal Doctrine, III Targeted Killing in Contemporary Legal Doctrine

From: Targeted Killing in International Law

Nils Melzer

Subject(s):
Targeted killing — Military objectives — Self-defence — Armed attack — Derogations

(p. 44) III  Targeted Killing in Contemporary Legal Doctrine

In reviewing the contemporary legal doctrine with regard to State-sponsored targeted killings, it is possible to distinguish at least three different discussions. The first, and most recent discussion, is concerned with the international lawfulness of the respective policies of targeted killing adopted by States such as Israel, the United States, Pakistan, and Russia in their current counter-terrorism campaigns. A second, more specific discussion involves primarily American writers and focuses on the concept of ‘assassination’ under international and US domestic law. A third, geographically fragmentalized, discussion takes place in parallel, generally not interrelated, national fora and addresses the permissibility of ‘shoot-to-kill’ policies under the law enforcement standards of the respective domestic legislations.

In line with the scope of the present analysis, the following overview will leave aside aspects of national law, and try to connect those strands of the various debates that are relevant for the permissibility of targeted killings under international law.1 To that end, it will be necessary to clarify the origin, scope and definitional basis of the American discussion on ‘assassination’ as compared to the current discussion based on the more general concept of ‘targeted killing’.2 As far as international law is concerned, the discussion on targeted killing is typically conducted under one or several of the three principal normative frameworks which regulate the use of force by States, namely the law governing the resort to interstate force,3 international humanitarian law (IHL)4 and human rights law.5 It is characteristic for most analyses that human rights law is generally equated with the ‘standard’, ‘model’, ‘pattern’ or ‘paradigm’ of law enforcement, IHL with (p. 45) the paradigm of hostilities, and the law of interstate force with the paradigm of self-defence. In examining the method of targeted killing, several authors have recently tried to overcome this rigid classification, particularly by pointing out that, due to their common teleological bases and often simultaneous applicability, the interaction between human rights law and IHL is more sophisticated than suggested by the maxim of lex specialis generalibus derogat. Others have even concluded that the lex lata of human rights law, IHL and the law of interstate force has become inadequate, and must be supplemented by a new normative paradigm tailor-made particularly for extraterritorial counter-terrorism operations. The resulting progressive approaches will be briefly evaluated as to their significance, potentials and limitations6 before outlining the scope, rationale and conceptual approach of the present analysis.7

1.  American Discussion on Assassination

The discussion on ‘assassination’ involves primarily writers from the United States8 and dates back to Cold War practices of the US Government in the 1960’s and 1970’s, and the related investigation by the US Senate Select Committee (Church Committee) into alleged CIA involvement in plots to assassinate foreign leaders.9 The Church Committee’s 1975 report, and its recommendation of a statutory prohibition of assassination led consecutive US Presidents to forego such legislation by passing executive orders (currently EO 12333 of 1981) banning US Government agents from engaging in assassination.10 However, the failure of EO 12333 and its predecessors to provide a definition of assassination left US administrative officials and military personnel without guidance as to the interpretation of the presidential order and the resulting boundaries for their (p. 46) conduct of affairs.11 The ensuing discussion in the American legal doctrine—not surprisingly in view of the general scope of the ban—preconceives assassination to be unlawful by definition, and is dominated by the question as to what conduct would fall under or, even more importantly, escape the scope of the ban.12 This preconception of unlawfulness, in conjunction with historical and other factors, favors a peacetime concept of assassination that is significantly broader than the corresponding wartime concept.13

According to the prevailing American legal doctrine, the peacetime concept of assassination essentially denotes the killing of selected individuals that is both politically motivated and illegal.14 This definition is deduced from a conglomerate of sources such as the Organization of African Unity (OAU) Charter,15 bilateral extradition treaties containing an ‘attentat-clause’,16 and the New York Convention on the Prevention and Punishment of Crimes against Internationally Protected Persons (1973).17 Additionally, the definition is inferred from the prohibition of murder in all national legislations, from the universal prohibition of interstate force in Article 2(4) UN Charter,18 as well (p. 47) as from the practice of individual States19 and of the United Nations20 with regard to particular cases of assassination. It is likely that the resulting equation in US doctrine of peacetime assassination with politically motivated murder also best corresponds to the intended scope of the presidential ban on assassination, which was construed as a response to the Church Report on alleged CIA involvement in plots of political murder. From a contextual perspective, as far as peacetime assassination is concerned, the US doctrine focuses entirely on targeted killings occurring in interstate relations, and completely disregards the practical relevance of political murder in domestic law enforcement situations.21 Moreover, from a normative perspective, the permissibility of targeted killings in peacetime is analyzed exclusively under the law regulating the use of force between States, but not under the law regulating the use of lethal force by States against individuals. Quite surprisingly for a sophisticated discussion on the international lawfulness of State-sponsored targeted killing outside situations of armed conflict, none of the authors involved acknowledges the existence of human rights law, or discusses the material and territorial scope of the human right to life.22 Instead, the discussion of peacetime assassination is reduced to an issue of Article 2(4) UN Charter, and the conventional and customary right of self-defence. Despite its regrettable silence on questions of domestic law enforcement and human rights law, the American discussion on peacetime assassination contributes significantly to the general debate on the permissibility of targeted killings under the law of interstate force.

The wartime concept of assassination as construed in the prevailing American legal doctrine refers exclusively to the treacherous killing of a selected individual belonging to the adversary.23 Although this extremely narrow definition is deduced (p. 48) from the prohibition of assassination in the Lieber Code (1863), and from the prohibition of treachery and perfidy in conventional humanitarian law, these sources to not persuasively point to an equation of assassination with treacherous killing. For example, while Article 148 Lieber Code expressly prohibits ‘assassination’, the text of this provision indisputably refers to the extrajudicial killing of captured adversaries and not to treachery, which is already prohibited in Article 101 Lieber Code.24 And while Article 8 of the Oxford Manual (1880) prohibits ‘treacherous attempts upon the life of an enemy; as for example [sic!] by keeping assassins in pay’, the mere fact that treacherous killings may be committed by way of assassination does not necessarily entail that the concept of assassination must be restricted to treacherous killing. In any case, no international instrument other than the Oxford Manual makes a clear link between treacherous killing and assassination.25 Where national military manuals contain a specific prohibition of assassination, it is based on diverging definitions of assassination, which sometimes—but not always—include the element of treachery:26

Australia: ‘Assassination is the sudden or secret killing by treacherous means of an individual who is not a combatant, by premeditated assault, for political or religious reasons. Assassination is unlawful’ [emphasis added].27

Canada: ‘Assassination is prohibited. Assassination means the killing or wounding of a selected non-combatant for a political or religious motive’.28

Israel: ‘An attempt on the lives of enemy leaders (civilian or military) is forbidden. As a rule, it is forbidden to single out a specific person on the adversary’s side (p. 49) and request his death (whether by dispatching an assassin or by offering an award for his liquidation)’.29

New Zealand: ‘Assassination, that is, the killing or wounding of a selected individual behind the line of battle by enemy agents or unlawful combatants is prohibited’.30

United Kingdom: ‘Assassination, the killing or wounding of a selected individual behind the line of battle by enemy agents or partisans, and the killing or wounding by treachery of individuals belonging to the opposing nation or army, are not lawful acts of war’ [emphasis added].31

United States: ‘It is especially forbidden to kill, or wound treacherously, individuals belonging to the hostile nation or army. [Article 23 [1] (b) H IV R] This article is construed as prohibiting assassination, […]’ [emphases added].32

The respective manuals additionally make it clear that the prohibition of assassination also prohibits outlawing, or putting a price on the head of, an individual enemy or making offers for an enemy ‘dead or alive’,33 but that it does not prohibit surprise attacks against individual combatants of the enemy, whether in the zone of hostilities, occupied territory, or elsewhere.34 In fact, more than anything else, the equation of wartime assassination with treachery seems to be a remnant of a historical discussion on assassination inspired by writers such as St. Thomas Aquinas (13th century), Sir Thomas More (16th century), Alberico Gentili and Hugo Grotius (17th century), Emmerich de Vattel and Cornelius van (p. 50) Bynkershoek (18th century).35 Just as any other historical discourse, these texts reflect the social, political, and military context and address the theoretical questions and practical problems of their time. Between the 13th and 18th centuries, the question as to whether the sovereign or military leader of a nation at war could lawfully be killed had a legal, political and moral significance, which cannot be compared to modern perceptions. Even from a purely practical perspective, before the advent of weapons precise and powerful enough to kill a selected individual from a safe distance, the resort to treachery must regularly have been the only realistic option of approaching a ‘high value target’ without losing the element of surprise. In sum, it remains doubtful whether an international consensus has actually formed with regard to this narrow, and predominantly historical, definition of wartime assassination.36 Moreover, in view of the already existing prohibition of treacherous killing in customary and conventional IHL, some authors have rightly questioned the purpose of such a restricted concept of assassination, and have made proposals ranging from its modernization to discarding it altogether.37 Indeed, the targeted killing of selected individuals during the conduct of hostilities raises numerous issues unrelated to treachery, such as questions pertaining to the consequences of civilian participation in hostilities, the prohibition of denial of quarter, the ban on certain weapons, and the interpretation of the principles of military necessity, precaution and proportionality in contexts of modern warfare.

In the final analysis, it cannot be disputed that the American discussion on ‘assassination’ has its own place, and significance, in the wider debate on targeted killings. In appreciating the scope and perspective of this discussion, it must, however, be kept in mind that its primary purpose is to provide guidance for the interpretation of a particular instrument of domestic governance, which prohibits the involvement of US Government agents in assassinations. Therefore, this discussion does not constitute, nor is it intended to be, a comprehensive analysis of the permissibility of State-sponsored targeted killings under international law. The American discussion is based on definitions of assassination which are not universally consolidated, and which differ significantly in wartime and peacetime. This may lead to confusion as to the applicable definition, particularly in situations of non-international armed conflict, in occupied territories, and in grey-zone contexts involving a significant level of violence without clearly qualifying as armed conflicts. Although the discussion on peacetime assassination provides valuable insights concerning the permissibility of targeted killings under the law (p. 51) of interstate force, it completely disregards not only the practical relevance of political murder in domestic law enforcement situations, but also the general relevance of human rights law for the international lawfulness of State-sponsored targeted killings. Moreover, while the equation of wartime assassination with treacherous killing has resulted in a thorough examination of the prohibition of treachery specifically with regard to the method of targeted killing, which constitutes a valuable contribution to the present analysis, the resulting definition of wartime assassination is far too narrow to allow a comprehensive analysis of the international lawfulness of targeted killings during the conduct of hostilities.

2.  Discussion of Targeted Killing under the Law of Interstate Force

Authors generally agree that, in principle, the resort by a State to targeted killings within another State falls under the prohibition on interstate force expressed in Article 2(4) UN Charter and, in order to be justified, requires either a situation of interstate self-defence,38 or an authorization on the part of the territorial State,39 or the UN Security Council.40 To the knowledge of the present author, however, no detailed analyses have been conducted as to potential limits imposed by the law of interstate force specifically on the authority of States to consent to targeted killings on their territory,41 and on the power of the UN Security Council to authorize targeted killings against selected individuals.42 Some authors analyze the permissibility of extraterritorial targeted killings exclusively under the law of interstate force, and seem to disregard the fact that (p. 52) that this law regulates only the relations between States, and not those between States and individuals.43 Most others correctly emphasize, however, that, even if justified under the law of interstate force, the international lawfulness of a particular targeted killing additionally depends on the law protecting individuals from arbitrary deprivation of life, namely human rights law and, in the case of armed conflict, IHL.44

Two scenarios dominate the discussion of targeted killings in the context of the right of self-defence. First, targeted killings are contemplated as a pre-emptive measure against the leader of a ‘rogue’ State aiming to acquire weapons of mass destruction (WMD), such as most recently in the case of Iraqi President Saddam Hussein.45 Second, targeted killings are discussed as a defensive measure against members of transnational terrorist groups operating from the territory of another State, such as al-Qaida or certain Palestinian militant groups.46 In both cases, the main difficulties arise in relation to the prerequisite of an ‘armed attack’. Most authors agree that massive terrorist attacks, such as those carried out in New York City and Washington DC on 11 September 2001, or regular terrorist attacks of a comparatively minor scale, such as the frequent Palestinian suicide bombings carried out in Israel, can potentially qualify as an ‘armed attack’ within the meaning of Article 51 UN Charter.47 Many authors also interpret the right of self-defence in light of the Caroline Case (1837), concluding that it justifies military action not only against States, but also against non-State actors in the territory of a different State, particularly where the territorial State fails to prevent cross-border attacks by these non-State actors against the defending State.48

(p. 53) More problematic is the permissibility of ‘anticipatory’ targeted killings aiming to prevent an armed attack by transnational terrorists or by a ‘rogue’ State, where such an attack is neither occurring nor imminent, but nevertheless likely to occur in the foreseeable future.49 Supporters of anticipatory self-defence essentially claim that the UN Charter has not restricted the pre-existing customary right of self-defence. Moreover, the clandestine character, transnational organization, and enormous destructive potential of modern terrorism or of ‘rogue States’ equipped with WMD is held to require the permissibility of targeted killings in a moment when the suspected perpetrators are visible, and not only when the planned terrorist, nuclear, biological or chemical attack is already imminent or in the process of being carried out.50 American authors in particular tend to overstretch the phrase ‘if an armed attack occurs’ in Article 51 UN Charter to justify self-defensive action not only against ‘an actual use of force, or hostile act’ or ‘an imminent use of force’, but also against so-called ‘continuing threats’.51 Conversely, those rejecting anticipatory self-defence contend that, according to the clear wording of Article 51 UN Charter, any use of interstate force is unlawful prior to the moment where a concrete ‘armed attack’ actually occurs or is obviously imminent. If permitted, such anticipatory self-defence would lead to arbitrary use of force based on speculation or, at best, unverifiable information provided by intelligence agencies.52 The risks and arbitrariness inherent in the doctrine of anticipatory self-defence received incontrovertible proof in the 2003 invasion of Iraq. Invoking a purported right of anticipatory self-defence, the United States and the United Kingdom based their invasion entirely on unsubstantiated, and widely doubted, claims that Iraq possessed and produced WMD. As these claims subsequently proved to lack any factual basis, the invasion and occupation of Iraq by the coalition forces clearly violated Article 2(4) UN Charter.53

In their search for operable and acceptable standards for the resort to extraterritorial targeted killings, some authors have proposed proceeding by analogy (p. 54) with a concept of ‘necessity’ derived from domestic criminal law.54 In their view, a targeted killing would be justifiable if the harm sought to be avoided is greater than that sought to be prevented by prohibiting that targeted killing.55 It is characteristic of this approach, that the proposed standard of ‘necessity’ determines the permissibility of the use of lethal force not only as far as it infringes the territorial sovereignty of another State, but simultaneously also with regard to the right to life of the targeted individual and uninvolved bystanders. In other words, a targeted killing would be lawful ‘when the harm posed by the continued life of the target is greater than the harm that would result from violating the sovereignty of another nation, killing without due process and the possibility of killing innocents’.56 As far as the threshold requirement for the lawful use of interstate force is concerned, the proposed approach replaces the objective prerequisite of an ‘armed attack’ by an unsophisticated proportionality test balancing two possible harms in order to determine whether ‘the benefits outweigh the costs’.57

The proposed analogy with domestic criminal law does not withstand theoretical and methodological scrutiny, most notably for two reasons: first, both the Caroline Case and the ILC Draft Articles on State Responsibility illustrate that customary international law already recognizes an exculpatory concept of necessity, which may well be able to achieve the desired results in a theoretically consistent manner. The relevant question is not whether the perceived dysfunction of the law of interstate force can somehow be ‘fixed’ by domestic criminal law. Instead, the decisive question must be to what extent Article 2(4) UN Charter permits exceptions based on exculpatory concepts recognized in general international law, but not expressly mentioned in the UN Charter, such as consent, necessity or distress. In the view of the present author, a strong case could be made that, while the intentional use of interstate force in the absence of a recognized exculpatory circumstance would generally fall under the peremptory prohibition of aggression, the existence of consent, necessity or distress as defined in the ILC Draft Articles would have the contrary effect, namely of justifying the recourse to interstate force.58 Should this argument be rejected based on the peremptory nature of the prohibition of interstate force formulated in the UN Charter, then that prohibition most definitely could not be overruled by an improvised standard derived from an ‘analogy’ with a particular system of domestic criminal law. Second, the proposed approach conflates the two distinct legal questions as to the lawfulness of a targeted killing with respect (p. 55) to the injured State on the one hand (law of interstate force), and with respect to the targeted individual on the other (human rights law and IHL). As a result, an unsophisticated proportionality test balancing the overall harm expected from a targeted killing against the overall harm expected if that targeted killing does not occur would be sufficient to take exception from the entire law of interstate force, as well as from human rights law, and IHL. It is indeed hard to see how such deregulation could be beneficial to the respect for State sovereignty, the protection of human life, and the general respect for the rule of law.

In sum, there can be no doubt that the law of interstate force as it stands today requires clarification, particularly with regard to operations that are directed exclusively against non-State actors, and involve force of no more than minimal intensity. A methodologically and theoretically sound refinement of the law of interstate force cannot, however, be achieved without a profound, and comprehensive, understanding of the principles underlying general international law. Relying on unwarranted ‘analogies’ to escape the meticulous juridical efforts required for such a clarification and refinement will inevitably lead to unsustainable results.

3.  Discussion of Targeted Killing under International Humanitarian Law

Analyses on the international lawfulness of targeted killings often begin by questioning whether these operations are governed by IHL or by human rights law. As far as the applicability of IHL is concerned, it is generally recognized that it presupposes the existence of a situation of armed conflict. Most legal analyses focusing on the policies of targeted killing adopted by Israel and the United States address the question as to whether the Israeli-Palestinian confrontation,59 and the so-called ‘war on terrorism’60 can be regarded as an international or non-international armed conflict within the meaning of IHL. The diverging conclusions reached by the authors involved suggest that the legal concept of ‘armed conflict’ requires further clarification. Particularly the Israeli-Palestinian context of belligerent occupation also raises the question as to what extent a party to (p. 56) the conflict, and especially an occupying power, must comply with human rights standards despite the applicability of IHL.61 In this respect it is generally found that, outside the conduct of hostilities, the use of lethal force against civilians must be governed by the human rights standard of strict necessity.62

As far as the conduct of hostilities is concerned, there is general agreement that, in principle, the resort to targeted killings is permissible as long as the targeted individuals are legitimate military targets, that is to say, combatants or civilians directly participating in hostilities.63 The discussion of the principle of distinction is greatly influenced by the fact that almost all targeted killings are directed against non-State actors, and that they are generally carried out while the targeted person is not visibly engaged in active combat. Thus, it is questioned whether organized armed non-State actors engaged in an armed conflict against a State should be regarded as civilians, who may be targeted only for such time as they directly participate in hostilities, or as unprivileged combatants, who may be attacked on a permanent basis.64 To the extent that they are found to be civilians, it is discussed which activities would amount to ‘direct participation in hostilities’, and for how long a civilian directly participating in hostilities may be directly attacked.65 Some authors tend to shortcut the technicalities of IHL by equating (suspected) ‘terrorists’ with legitimate military targets, an approach without juridical merit that creates more definitional problems than it resolves.66

(p. 57) Brief remarks by a number of authors suggest that the requirement of military necessity prohibits the targeted killing of an individual combatant (or civilian directly participating in hostilities) in a situation where such killing is militarily unnecessary, either because it offers no military advantage or because the targeted person could have been captured without unreasonable risk to the operating forces.67 Moreover, apart from rare exceptions,68 there is general agreement that targeted killings must comply with the prohibitions of treachery and perfidy.69 In this respect, targeted killings conducted through air strikes from clearly marked military aircraft do not raise much concern, whereas the use of undercover commandos disguising themselves as civilians is seen as problematic.70 Finally, throughout the discussion on targeted killings under IHL, serious concerns are voiced with regard to the high probability of erroneous targeting,71 and of incidental death and injury among the civilian population.72

In sum, the most pressing legal questions generally recognized as arising under IHL concern the qualification of a confrontation between armed non-State actors and States as an armed conflict, the definition of combatancy and direct participation in hostilities in both international and non-international armed conflict, and the standards of precaution and proportionality to be applied to targeted killings. Moreover, the precise implications of the requirement of military necessity for the permissibility of targeted killings, the general concept of hostilities and the standards established by IHL for the use of lethal force outside situations of hostilities, merit more detailed research. Finally, there has been no meaningful discussion on the prohibition of denial of quarter, and the ban on certain weapons, (p. 58) specifically with regard to operations of targeted killing. All of these issues shall in the following be thoroughly analyzed.73

4.  Discussion of Targeted Killing under Human Rights Law

One of the central preliminary questions addressed in the discussion on the permissibility of State-sponsored targeted killing concerns the temporal and territorial scope of applicability of human rights law. The prevailing opinion is that, apart from specifically permitted derogations, human rights law is the body of law that protects all human beings at all times, including in times of armed conflict or other national emergency.74 While authors analyzing the Israeli policy of targeted killing emphasize the widely recognized applicability of human rights law in occupied territories,75 others more generally contend that the use of lethal force must comply with law enforcement standards to the extent that a State exercises effective or partial control over the concerned territory.76 Some authors go even further in dissociating the binding force of human rights obligations from territorial considerations and hold that the duty of a State to ‘respect’ (ie not to interfere with) the right to life, as opposed to its duty to ‘ensure’ (ie to actively protect) that right, ‘follows its agents wherever they operate’.77 Authors generally agree that the law enforcement standard of human rights law becomes inadequate when the violence between a State and organized armed non-State actors reaches the threshold of a non-international armed conflict.78 Nevertheless, it has rightly been emphasized that the inability of a State to apprehend individuals whose arrest would normally be permitted by the law does not necessarily entail that their killing becomes lawful.79 It is therefore widely held that, even in armed conflict, the use of lethal force against all persons who are not legitimate military targets must comply with human rights standards.80

(p. 59) The permissibility of targeted killings in light of the right to life is usually examined based on the main international human rights conventions, and the jurisprudence of their respective implementing bodies.81 Additional guidance is found in the practice of UN Charter-based human rights institutions, most notably the former UN Human Rights Commission (now Human Rights Council) and its Special Rapporteurs, as well as in UN-sponsored instruments such as the Universal Declaration of Human Rights, the UN Code of Conduct for Law Enforcement Officials (1979) and the UN Basic Principles on the Use of Force and Firearms by Law Enforcement Officials (1990). Whether a deprivation of life is ‘arbitrary’ is determined in the light of the circumstances of each particular case.82 It is generally recognized that the use of lethal force under human rights law is governed by the ‘strict’ or ‘absolute’ necessity, which requires that the use of lethal force be indispensable to avert a concrete threat, and the principle of proportionality, which requires that the use of lethal force be justified in view of the gravity of that threat.83 Particularly with regard to the use of lethal force with the intention to kill, some authors emphasize the temporal aspect of absolute necessity, namely the requirement of immediacy, which allows for no delay in responding to a concrete and grave threat.84 Apart from that, the difference between force which actually intends to kill, and force which aims to incapacitate but is almost certain to kill is either deemed to be insignificant or is not addressed at all.85

Under the requirement of absolute necessity, the use of lethal force is held to be permitted only as a last resort, when no non-lethal means are available that could reasonably be expected to avert the danger in question.86 The requirement of proportionality, on the other hand, entails that the right to life tends to override the interests of law enforcement.87 Strictly speaking, the purpose of lethal force must not be to kill, but to render the targeted person incapable of attack or escape, and its proportionality is not measured by reference to the gravity of a perpetrator’s past offence, but by reference to the gravity of the concrete danger which he or she continues to represent.88 It is generally found that, under human rights law, targeted killings are permitted only in the most extreme circumstances, such as to prevent a concrete and immediate danger of death or serious physical injury, and that there is a strong presumption that intentional deprivations of life are in (p. 60) violation of the right to life.89 Throughout the discussion, it is also emphasized that, under human rights law, lethal force may be used only for preventive purposes, and not as a sanction for past offences.90 It is recalled that the authority to punish perpetrators, and particularly to impose the death penalty, rests with the judicial authorities, and cannot be delegated to armed forces or intelligence services.91 There is widespread concern that the lack of independent scrutiny may lead to arbitrary or erroneous targeting decisions,92 and may also amount to a violation of the right to a fair trial.93

In sum, the reviewed literature suggests that the standards governing the permissibility of targeted killings under human rights law are consolidated and relatively uncontroversial. Nevertheless, the precise implications of the distinction between potentially lethal force, and force used with the intention to kill have received only cursory attention. Likewise, it will be worthwhile to examine whether extreme circumstances, such as ongoing hostilities or the threat of a massive terrorist attack, can significantly influence the interpretation of the requirements of absolute necessity and proportionality. Overall, however, the most important questions to be clarified with regard to the permissibility of State-sponsored targeted killings under human rights law relate to the applicability of that body of law much more than to the interpretation of its standards. Thus, it remains unclear as to what extent States are bound by the conventional right to life beyond situations of territorial law enforcement. Furthermore, it should be clarified whether the right to life can also be derived from other sources of international law, such as custom and general principles of law, and what the implications of an affirmative answer would be. These questions shall therefore be thoroughly analyzed.94

5.  Specific Progressive Approaches

5.1.  Ben-Naftali and Michaeli

Ben-Naftali and Michaeli analyze the Israeli policy of targeted killing under three different normative frameworks, which they consider to be simultaneously (p. 61) applicable to the situation, namely human rights law and the rules of IHL both on belligerent occupation and on the conduct of hostilities. In view of the perceived contradictions and discrepancies between these normative frameworks, the authors propose to apply an integrative approach based on their common teleological basis, namely the protection of human dignity and physical integrity, and the limitation of human suffering.95 This leads the authors to the following conclusions: during combat situations, the targeted killing of combatants and of civilians directly participating in hostilities is permitted subject to the general rules on the conduct of hostilities.96 Outside combat situations, combatants only exceptionally constitute legitimate targets, namely when all other means to apprehend them fail.97 Non-combatants, including civilians who do not or no longer take a direct part in hostilities, and non-combatant members of military organizations, may never be targeted, regardless of whether an arrest is feasible.98 In view of these criteria, the authors conclude that while a specific targeted killing may be lawful, a general policy of targeted killings cannot.99 For the purpose of this analysis, the most significant conclusions reached by Ben-Naftali and Michaeli are that, in situations of armed conflict, human rights law not only has a complementary role where the lex specialis of IHL provides no clear answers, but that it also affects the interpretation of specific provisions of IHL in a manner that puts additional emphasis on humanitarian aspects and priorities when determining the legitimacy of military actions.100

5.2.  Cassese

In his expert opinion on the Israeli policy of targeted killings submitted to the Israeli Supreme Court, Cassese asserts that, under IHL, only combatants and civilians directly participating in hostilities may be lawfully targeted.101 Conversely, civilians not currently engaged in military action cannot be lawfully targeted, even if they are suspected of terrorism.102 The author interprets ‘direct participation in hostilities’ as being restricted to actual engagement of civilians in combat, as well as the open carrying of arms during military deployments preparatory to an attack, and comes to the conclusion that, in any other circumstances, the targeting of civilians is prohibited under IHL.103 Having derived this strict regime from IHL, Cassese nevertheless doubts its practical viability with (p. 62) regard to Palestinian suicide bombers infiltrating Israel as ‘[i]t would be preposterous to require that Israelis be authorized to open fire against such Palestinians only if they carry their explosives openly’.104 Cassese therefore turns to the strict standards applied by the European Court of Human Rights to the use of lethal force in counter-terrorist operations, and concludes that targeted killings may also be justified where suspected suicide bombers do not respond to a summons or—if compelling reasons absolutely exclude a summons—where it is ‘manifest’ that they are concealing explosives on their body.105 The significance of Cassese’s reasoning for the present analysis lies, first, in the observation that the specific circumstances prevailing in a context may indeed affect the standards by which lethal force may lawfully be used. Second, in taking these circumstances into account, Cassese does not make the notion of ‘direct participation in hostilities’ and, thereby, the criteria governing lawful targeting under IHL, more flexible but the requirements of precaution, absolute necessity and proportionality of human rights law. Consequently, in a situation where the threat posed by a civilian not directly participating in hostilities reaches proportions that are comparable to a military attack, that civilian does not become a military target, but the standards of human rights law are interpreted more generously to meet the objective nature of that threat.

5.3.  Kremnitzer

According to Kremnitzer, where a State resorts to targeted killings in domestic law enforcement, such operations must comply with the human rights standard of ‘absolute necessity’. While the use of lethal force in law enforcement must, in principle, aim to incapacitate the targeted person, an actual ‘intention to kill’ may exceptionally also be permissible where there is no other way to prevent an almost certain, concrete and immediate danger to life or a threat of serious physical injury.106 Kremnitzer holds that law enforcement standards apply without exception wherever a State has effective control. In case of partial control, it would be preferable to operate under the law enforcement paradigm rather than to resort to belligerent action, at least to the extent that this is feasible without unduly endangering the lives of the soldiers or civilians involved.107 Kremnitzer emphasizes that the physical inability of a State to apprehend individuals whose arrest would normally be permitted by the law does not entail that their killing becomes lawful, unless there is an independent justification for the use of lethal force.108 The targeted killing of individual terrorists would, therefore, normally remain subject to law enforcement standards even during cross-border operations without the (p. 63) consent of the territorial State.109 In view of the problems arising from responding to terrorist threats solely through law enforcement measures, Kremnitzer holds that there is a need for more appropriate methods of counter-terrorism, particularly with regard to suicide bombers preparing their attacks in States incapable or unwilling to prevent their activities.110 A possible approach would be to apply IHL to counter-terrorist activities as soon as the threshold of intensity required for an armed conflict is reached.111 Kremnitzer observes that targeted killings go against the logic of de-personalized warfare between collective entities, and estimates that the ‘personalization and individualization of military aims could cause the collapse of the conventional view of war and the justification for killing in its context’.112 He recognizes, however, that existing law regulating the conduct of hostilities does not prohibit the singling out of a specific individual, as long as the operation is directed against a combatant or a civilian directly participating in hostilities and does not involve treacherous means.113 Kremnitzer contends that, in view of the inherent risk of erroneous or arbitrary targeting, ‘suspected’ terrorists may not be considered as legitimate targets, but must be treated according to human rights law.114 Only when individuals proclaim themselves openly, and unequivocally, as leaders of a terrorist organization or as active terrorists, would there be sufficient evidence that these individuals directly participate in hostilities and may therefore be targeted.115 For the present analysis, the most significant arguments made by Kremnitzer are the following: first, the use of lethal force against individual terrorists in cross-border operations without consent of the territorial State is governed by law enforcement standards even though it gives rise to a situation of international armed conflict. Second, in case of doubt as to whether an individual targeted during the conduct of hostilities constitutes a legitimate military target, the use of lethal force must comply with the standards of human rights law.

5.4.  Ruys

In examining the human right to life, Ruys remarks that the requirements of necessity and proportionality of the use of lethal force come remarkably close to the principles of necessity and proportionality used as targeting principles in IHL.116 While necessity refers to the requirement to exhaust all available nonlethal means, proportionality demands that a careful balance be struck between the goal to be achieved and the means used to this end.117 Arbitrariness must be tested on a case-by-case basis, taking into account the whole context of an incident. According to Ruys, there is a strong presumption that intentional deprivations of life are in violation of the right to life, unless it is proven that all attempts (p. 64) to arrest a person failed or would have been of no avail.118 Ruys asserts that even the existence of an armed conflict does not provide ‘carte blanche’ for the use of lethal force119 although, subject to the prohibition of treachery or perfidy, IHL essentially permits the singling out and killing of an individual combatant or civilian directly participating in hostilities.120 The main difficulty is to clarify what conduct constitutes direct participation in hostilities.121 Ruys contends that a ‘membership approach’, according to which all members of an organized armed group could be attacked at any time, would be too broad, because some members would never really engage in hostilities. In case of doubt, any person must be presumed to be a protected civilian.122 Targeted killings, therefore, should be permissible only against persons who are effectively preparing or engaging in an attack, including so-called ‘ticking bombs’. The use of lethal force against all other persons, including those suspected of previous involvement in terrorist attacks, should be governed by human rights law.123 The legality of targeted killings under IHL will often depend on the circumstances, and must therefore be assessed on a case-by-case basis.124 Overall, Ruys concludes that current international law governing the use of lethal force ensures a basic balance between the interests of State security, individual security, and civil liberties, and is effective when properly implemented.125 Apart from the controversy surrounding the meaning of the notion of ‘direct participation in hostilities’, international law provides a clear normative framework for State-sponsored targeted killings.126 According to Ruys, proposals to modify the existing frameworks with regard to terrorists and general shoot-to-kill policies such as the one practiced by Israel threaten to erode the rule of law and must be rejected.127 For the present purposes, the most significant observation is that, according to Ruys, the use of lethal force against any person who does not constitute a legitimate military target in a situation of armed conflict remains governed by human rights law and that, in case of doubt, any person must be presumed to be a protected civilian.

5.5.  Kretzmer

Kretzmer conducts an abstract analysis into the lawfulness of extraterritorial State-sponsored targeted killings against suspected terrorists.128 Kretzmer’s (p. 65) analysis does not follow the classic dividing lines between the law of interstate force, human rights law, and IHL, but applies two complementary normative paradigms (‘models’), each of which is derived from several, simultaneously applicable, normative frameworks. The ‘armed conflict model’ essentially comprises the law of interstate force and the provisions of IHL on the conduct of hostilities,129 whereas the ‘law enforcement model’ comprises human rights law and the rules of IHL on belligerent occupation.130

Kretzmer argues that the law enforcement model is inadequate when the violence between a State and a transnational terrorist group reaches the threshold of a non-international armed conflict, and the group operates from the territory of a State that is either unwilling or incapable of cooperating in law enforcement. In situations where law enforcement measures are in fact not available, States cannot be expected to use extraterritorial lethal force only in case of absolute necessity to counter an imminent threat as would be required under the law enforcement paradigm.131 Under IHL governing international armed conflict, however, armed non-State actors would generally have to be regarded as civilians who are subject to direct attack only for such time as they individually take a direct part in the hostilities. Kretzmer deduces that, after a cross-border attack by civilian non-State actors amounting to an ‘armed attack’ within the meaning of Article 51 UN Charter, the application of IHL governing international armed conflict would render the right of self-defence virtually meaningless. More concretely, as the relevant provisions of that law would not allow qualifying the attacking non-State terrorists as combatants, they would have to be regarded as civilians. Because IHL governing international armed conflict does not allow attacks against civilians who are not, at the time, directly participating in hostilities the self-defending State would not be able to target the actual terrorists directly, but would be obliged to wait passively until the next attack became imminent or was actually carried out.132 In discussing this scenario, Kretzmer does not address the alternative possibility of armed incursions by the self-defending State into the territorial State with the aim of apprehending the suspects in question. The terrorists being civilians, and the violence caused by them not amounting to a non-international armed conflict, the use of lethal force against them would have to comply with law enforcement standards, unless and for such time as they directly participate in hostilities which may arise between the self-defending and the territorial State. In analyzing the legal regime of IHL governing non-international armed conflict, Kretzmer comes to the conclusion that the fighting forces of both the State and the transnational terrorist group would have to be regarded as combatants as soon as the threshold requirements for a non-international armed conflict are (p. 66) met.133 Kretzmer subsequently discards this solution as too permissive, because ‘the state would seem to enjoy almost unlimited power to target persons it claims to be active members of that group, even when they pose no immediate danger and it might be feasible to apprehend them and place them on trial’.134 It remains unclear, however, whether Kretzmer rejects the idea of combatants constituting permanent military objectives for all non-international armed conflicts, only for those occurring outside the territory of the involved State party, or only for those involving transnational terrorist groups.

Based on these observations, Kretzmer jumps to the conclusion that neither the law enforcement model nor the armed conflict model provides an adequate framework for non-international armed conflicts between States and transnational terrorist organizations and proposes, presumably de lege ferenda, an intermediate framework that combines elements of both models, the so-called ‘mixed model’.135 In addressing the perceived inadequacies of the lex lata, Kretzmer essentially proposes to import the requirements of necessity and proportionality governing the exercise of the right of self-defence under Article 51 UN Charter into IHL governing the conduct of hostilities in non-international armed conflict.136 According to Kretzmer, the aim of incorporating the self-defence principle of necessity is to replace the targeting rules of IHL by a standard, which restricts the lawfulness of lethal force to situations where there is ‘credible evidence that the targeted persons are actively involved in planning or preparing further terrorist attacks against the victim State and no other operational means of stopping those attacks are available’.137 The declared function of the self-defence principle of proportionality, on the other hand, is to subject all extraterritorial targeted killings to a strict proportionality test, which would balance the threat posed by the continued activities of a suspected terrorist against the likelihood that his or her targeted killing might cause incidental civilian death and injury.138 The proportionality test would be conducted under the presumption ‘that suspected terrorists may not be targeted when there is a real danger that civilians will be killed or wounded too’.139

Quite regrettably in view of the laudable values he promotes, Kretzmer’s ‘mixed model’ does not withstand closer scrutiny. First, contrary to what is suggested, the standard of necessity applicable under Article 51 UN Charter is far too strict to permit targeted killings based on ‘credible evidence that the targeted persons are actively involved in planning or preparing further terrorist attacks (p. 67) against the victim State and [the lack of] other operational means of stopping those attacks’.140 This permissive standard contradicts the temporal aspect of the requirement of necessity under Article 51 UN Charter, which requires that an ‘armed attack’ is either imminent or in the process of occurring. Unfortunately, Kretzmer does not explore the possibilities of achieving similar results through a more refined and context-dependent interpretation of the principle of military necessity, which lies at the very basis of IHL and may provide useful guidance for its interpretation. Similarly, the proportionality test proposed by Kretzmer contradicts the proportionality concept underlying Article 51 UN Charter, while essentially corresponding to the proportionality test required during the conduct of hostilities. More specifically, while the proportionality tests under the law of self-defence and, respectively, human rights law balance the aim to be achieved against the harm done to the attacking State or the perpetrator, the proportionality test under IHL does not take into account the interests of the targeted person but, just as Kretzmer’s test, balances the aim to be achieved exclusively against the risk of collateral damage. Here too, it must therefore be questioned whether the results desired by Kretzmer, namely a presumption of ‘excessiveness’ for any targeted killing causing ‘collateral damage’, could not be achieved more persuasively through a more refined interpretation of the principle of proportionality inherent in IHL specifically with regard to targeted killings in situations of non-international armed conflict.

Overall, while not persuasive in its conclusion as to the inadequacy of the lex lata and the proposed solutions, Kretzmer’s analysis is extremely valuable in that it identifies, and clearly formulates, a number of critical legal questions related to the extraterritorial targeted killing of members of transnational terrorist groups. Most notably, careful consideration should be given to the question of combatancy in non-international armed conflict, and the interpretation of the principles of (military) necessity and proportionality in the conduct of military and law enforcement operations against selected individuals. Finally, in applying the complementary normative paradigms (or ‘legal models’), of law enforcement and armed conflict, rather than structuring his analysis along the classic dividing lines between the law of interstate force, human rights law, and IHL, Kretzmer provides a promising analytical approach based on contextual and conceptual rather than formal classifications, which deserves to be further developed.

5.6.  Heymann and Kayyem

Heymann and Kayyem affirm that, in situations of armed conflict, the use of lethal force is permitted only against legitimate targets. It would generally be lawful, therefore, ‘to target and kill any non-surrendering enemy combatant, in any place and at any time, regardless of what that combatant had done or was (p. 68) doing and regardless of whether that combatant posed an imminent threat or any individualized threat at all’.141 In peacetime, on the other hand, targeted killings must comply with human rights law—in the case of the United States the ICCPR—and the law governing interstate force.142 The authors recognize the difficulties of determining whether the ‘campaign against terrorists’ falls inside or outside the category of war.143 Without, however, subjecting any of these legal frameworks to a meaningful analysis they jump to the following conclusion:

in the gray area between war in the traditional sense and law enforcement in the ordinary sense in which counterterrorism actions are now being conducted, neither the general authority to attack personnel who may be lawfully engaged in combat roles under the law of war nor the strict law enforcement prohibition against targeted killing is appropriate.144

Heymann and Kayyem therefore recommend that the United States adopt clear and transparent standards for the use of targeted killing in their counter-terrorism campaign, and proceed to make a proposal of such standards. Estimating that it would be inappropriate to develop additional rules for zones of active combat and belligerent occupation, the authors focus on determining what circumstances would permit a targeted killing in situations ‘short of a general state of ongoing armed conflict’.145 The declared purpose of the recommendation is to supplement US domestic law, most notably previous Executive Orders, such as presidential EO 12333 banning assassination, but also criminal statutes regarding murders abroad, and the more general statutory provisions governing covert actions.146 In order to avoid arbitrary or erroneous targeting, the authors propose the following standard:

anywhere outside a zone of active combat, any targeted killing may be authorized only by the President and only when he finds, and provides the Congress with, evidence that the killing was necessary to prevent a greater, reasonably imminent danger to U.S. lives, that there was no reasonable alternative to save U.S. lives and that the action would not unreasonably endanger innocent individuals. Targeted killing cannot be an instrument of retributive punishment [emphases added].147

The terminology used is explained as follows: The notion of ‘zone of active combat’ essentially refers to a theatre of military operations related to an armed conflict (including belligerent occupation) between the United States or a State assisted by the United States on the one hand, and a foreign State, organization (p. 69) or defined class of individuals on the other.148 To be ‘necessary’ means that targeted killing is a practice of last resort where there is no other reasonable alternative; to be ‘reasonably imminent’ means that the development of an alternative (capture, arrest, etc.) would not eliminate a real likelihood of imminently threatened, lethal attack or would be inordinately dangerous to the operating forces; and, finally, to be ‘preventative’ means that the targeted killing may not be an instrument of retributive punishment, but must serve prospective purposes.149 According to Heymann and Kayyem, this standard would permit targeted killings ‘when the harm posed by the continued life of the target is greater than the harm that would result from violating the sovereignty of another nation, killing without due process and the possibility of killing innocents. In addition, the targeted killing must not involve danger to innocent individuals that is disproportionate to the harm to be prevented’.150 In other words, where a terrorist cannot be arrested, and unless a real likelihood of an imminent attack can be excluded, the targeted killing of that terrorist would be permitted where ‘the benefits outweigh the costs’.151

Conceptually, Heymann and Kayyem derive their proposed standard in part from exculpatory concepts of traditional criminal law, and in part from the alleged right of States to act in anticipatory self-defence.152 Although they recognize that, normally, the use of lethal force outside the conduct of hostilities is governed by human rights law, the authors do not show to what extent the standards proposed by them deviate from ordinary law enforcement standards applicable to counterterrorism operations on the one hand, and from the rules on the conduct of hostilities on the other. For example, the authors do not specify the criteria by which ‘greater’ danger to US citizens will be measured; they do not clarify whether, in order to be ‘necessary’, the envisaged targeted killing would have to be capable of eliminating, and likely to actually eliminate, the looming terrorist attack; nor does it transpire what standards, other than those applicable under IHL, would determine whether a targeted killing ‘unreasonably’ endangers innocent individuals. Nor do the authors compare the standard proposed by them to that applicable under the law of interstate force or the exculpatory principle of necessity as formulated in the ILC’s Draft Articles on State Responsibility. Moreover, the proposed test of ‘necessity’, (reasonable) ‘immediacy’, ‘preventive motivation’ and (not unreasonable) ‘proportionality’ conflates the law of interstate force, human rights law and IHL and replaces specific provisions of these regimes by a single set of criteria. This single set of criteria is subsequently applied to determine the permissibility of targeted killings not only with respect to the (p. 70) injured State, but also with respect to the targeted individual and uninvolved bystanders.153

Overall, Heymann and Kayyem undertake an attempt to subject targeted killings carried out by the United States in the course of its counter-terrorism campaign to strict regulation. As far as domestic procedure and review is concerned, their proposal can only be commended. In substantive terms, however, their analysis fails to position itself properly with respect to the international legal standards in force and their interpretation in doctrine and international jurisprudence. The resulting standards, therefore, remain diffuse and unable to honour the declared intent of the authors, namely to promote the rule of law with regard to State-sponsored targeted killing.

Footnotes:

1  Some cases and elements of discussion emerging from domestic fora will be addressed in the analytical part of this study with regard to their implications under international law.

2  See below, III.1.,pp.45 ff. While various definitions have been proposed for the term ‘targeted killing’, and while some authors include elements such as State-responsibility or extraterritoriality in the definition, most variations do not deviate far enough from the definition proposed in the present analysis to require a separate discussion. See above, I.1., pp. 3 ff.

3  See below, III.2., pp. 51 ff.

4  See below, III.3., pp. 55 ff.

5  See below, III.4., pp. 58 ff.

6  See below, III.5., pp. 60 ff.

7  See below, IV., pp. 71 ff.

8  See, pars pro toto, Kelly, Assassination in War Time; Parks, Memorandum EO 12333; Zengel, Assassination and the Law of Armed Conflict; Schmitt, State-Sponsored Assassination; Reisman, Reflections on Assassination and the Schmitt Formula; Scharf, Enforcing the International Ban on Biological and Chemical Weapons; Harder, Time to Repeal the Assassination Ban; Turner, It’s Not Really ‘Assassination’; Addicott, Proposal for a New Executive Order; Banks/Raven-Hansen, Targeted Killing and Assassination; Watkin, Humans in the Cross-Hairs; Yoo, Lecture AEI, June 2005; Solis, Assassination and American Armed Forces; Beres, Assassinating Saddam Hussein; Beres, American Doctrine of Preemption; Pickard, Legalizing Assassination?; Ulrich, The Gloves Were Never On.

9  ‘Church Report’: Alleged Assassination Plots Involving Foreign Leaders, An Interim Report of the Senate Select Committee to Study Governmental Operations with Respect to Intelligence Operations, S. Rep. No. 465, 94th Cong., 1st Session, Vols. 1 to 7 (1975). For a discussion of the report and its findings, see Schmitt, State-Sponsored Assassination, pp. 653 ff.; Zengel, Assassination and the Law of Armed Conflict, pp. 141 ff.; Banks/Raven-Hansen, Targeted Killing and Assassination, pp. 701 ff.

10  Section 2.11 EO 12333 (1981) states: ‘No person employed by or acting on behalf of the United States Government shall engage in, or conspire to engage in, assassination’.

11  Harder, Time to Repeal the Assassination Ban, p. 39; Schmitt, State-Sponsored Assassination, p. 679.

12  In US legal doctrine, assassination is generally restricted to cases of ‘murder’, that is to say, of unlawful homicide. See, for example, Parks, Memorandum EO 12333, p. 2; Zengel, Assassination and the Law of Armed Conflict, pp. 124 f.; Schmitt, State-Sponsored Assassination, pp. 627, 641; Reisman, Reflections on Assassination and the Schmitt Formula, p. 688; Scharf, Enforcing the International Ban on Biological and Chemical Weapons, p. 496; Harder, Time to Repeal the Assassination Ban, p. 5; Turner, It’s Not Really ‘Assassination’, p. 790; Addicott, Proposal for a New Executive Order, p. 761; Banks/Raven-Hansen, Targeted Killing and Assassination, p. 671; Watkin, Humans in the Cross-Hairs, pp. 169 f.; Yoo, Lecture AEI, June 2005; Solis, Assassination and American Armed Forces, p. 6. Skeptical: PickardLegalizing Assassination?, pp. 10 ff.

13  But see Pickard, Legalizing Assassination?, pp. 10 f., who defines assassination as ‘the targeted killing of an individual, by an official agent of a nation, regardless of whether a state of war exists’, and Heymann/Kayyem, Long-Term Legal Strategy, p. 5, according to whom ‘[t]argeted killing without trial and outside zones of armed conflict is assassination’.

14  Parks, Memorandum EO 12333, p. 2; Schmitt, State-Sponsored Assassination, pp. 627 f.; Harder, Time to Repeal the Assassination Ban, p. 6; Watkin, Humans in the Cross-Hairs, p. 169; Solis, Assassination and American Armed Forces, p. 6; Yoo, Lecture AEI, June 2005. But see Beres, Assassinating Saddam Hussein, pp. 847 ff. and Beres, American Doctrine of Preemption, pp. 157 ff., who proposes legalizing assassination as a measure of anticipatory self-defense and for exceptional cases, where the killing of a ‘tyrant’ may avoid genocide or crimes against humanity.

15  Art 3(5) OAU Charter unreservedly condemns State-sponsored political assassination.

16  See references in Schmitt, State-Sponsored Assassination, pp. 621 ff.

17  The New York Convention aims to prevent and punish crimes against internationally protected persons, but does not actually prohibit or criminalize them on the level of international law. Instead, the Convention obliges the States party to criminalize acts such as the intentional murder of internationally protected persons under their domestic legislations and to cooperate in matters such as prevention, prosecution and extradition of alleged offenders (Arts 2(1)(a), 3, 4, 7 and 8 New York Convention).

18  Schmitt, State-Sponsored Assassination, pp. 619 ff, referring both to the prohibition of murder in domestic law and the prohibition of interstate force.

19  Schmitt, State-Sponsored Assassination, pp. 623 ff., refers to US and UK jurisprudence in the cases of Letelier v Republic of Chile (US, 1980), Liu v Republic of China (US, 1989), Crown v Gill (UK, 1989), and Crown v Al-Banna (UK, 1984).

20  See, most notably, UNSC Resolution 611 of 25 April 1988 condemning the assassination by Israel of Abu Jihad in Tunis as an act of aggression.

21  In view of numerous reports of the UN Special Rapporteur on Extrajudicial, Summary or Arbitrary Executions and of human rights organizations on widespread practices of political murder (ie peacetime assassination), the conclusion that ‘[d]omestic law enforcement is not the problem; the problem is inappropriate means of settling international disputes’ (Schmitt, State-Sponsored Assassination, p. 680), seems too categorical.

22  One author recognizes, however, that a norm against assassination can be ‘inferred’ from human rights law, because it ‘suggests agreement on the wrongfulness of the taking of life’ (Schmitt, State-Sponsored Assassination, p. 620). None of the other authors referred to above, III., n. 8, makes any reference to human rights law. The absence of the human rights aspect in the discussion on assassination has also been remarked by Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, n. 104.

23  See, for example, Kelly, Assassination in War Time, pp. 102 ff.; Parks, Memorandum EO 12333, p. 4; Zengel, Assassination and the Law of Armed Conflict, p. 131; Schmitt, State-Sponsored Assassination, p. 641; Scharf, Enforcing the International Ban on Biological and Chemical Weapons, p. 496; Harder, Time to Repeal the Assassination Ban, p. 4; Addicott, Proposal for a New Executive Order, p. 783; Banks/Raven-Hansen, Targeted Killing and Assassination, p. 671; Watkin, Humans in the Cross-Hairs, p. 170; Watkin, Canada/US Interoperability, n. 129, p. 309; Solis, Assassination and American Armed Forces, p. 6. Unconvinced, however, Reisman, Reflections on Assassination and the Schmitt Formula, p. 688; Beres, American Doctrine of Preemption, p. 162; Raines, Just War Doctrine and Targeted Killings, pp. 238 f.

24  The Lieber Code states in Section IX (‘Assassination’), Art 148: ‘The law of war does not allow proclaiming either an individual belonging to the hostile army, or a citizen, or a subject of the hostile Government, an outlaw, who may be slain without trial by any captor, any more than the modern law of peace allows such intentional outlawry; on the contrary, it abhors such outrage. The sternest retaliation should follow the murder committed in consequence of such proclamation, made by whatever authority. Civilized nations look with horror upon offers of rewards for the assassination of enemies as relapses into barbarism’ [emphases added].

25  See Art 13 Brussels Declaration (1874); Art 15 Oxford Manual of Naval War (1913); Art 23(b) H IV R (1907) and Art 37 AP I (1977).

26  See the additional examples provided in: Henckaerts/Doswald-Beck, Customary IHL, Vol. II, Chapter 18, §§ 935 to 961.

27  Australia, Defence Force Manual (1994), §§ 724 and 725, cited in: Henckaerts/Doswald-Beck, Customary IHL, Vol. II, Chapter 18, § 936. See also Australia, Commanders’ Guide (1994), §§ 919 and 920, cited: ibid, § 937: ‘Assassination is the killing or wounding of a selected individual behind the line of battle by enemy agents or unlawful combatants, and is prohibited’.

28  Canada, LOAC Manual (1999), p. 6-3, §§ 25–7. The prohibition of perfidy, on the other hand, is laid down separately at: p. 6-2, § 8 (land warfare), p. 7-2, § 16 (air warfare) and pp. 8–10, § 80 (naval warfare). Cited in: Henckaerts/Doswald-Beck, Customary IHL, Vol. II, Chapter 18, § 940.

29  Israel, Manual on the Laws of War (1998), p. 57, cited in: Henckaerts/Doswald-Beck, Customary IHL, Vol. II, Chapter 18, § 944.

30  New Zealand, Military Manual (1992), § 507. The prohibition of perfidy, on the other hand, is laid down separately at: §§ 502(5) (land warfare), 713(2) (naval warfare) and § 1704(2)(b) (qualification as a war crime). Cited in: Henckaerts/Doswald-Beck, Customary IHL, Vol. II, Chapter 18, § 949.

31  UK, Military Manual (1958), §§ 115–16. The prohibition of perfidy, on the other hand, is laid down separately at: § 311. Cited in: Henckaerts/Doswald-Beck, Customary IHL, Vol. II, Chapter 18, § 957.

32  US Field Manual 27-10 (1956), § 31, cited in: Henckaerts/Doswald-Beck, Customary IHL, Vol. II, Chapter 18, § 959. Similarly also US Air Force Pamphlet (1976), § 8-6(d), cited: ibid, § 960.

33  Australia, Defence Force Manual (1994), §§ 724 and 725, cited in: Henckaerts/Doswald-Beck, Customary IHL, Vol. II, Chapter 18, § 936; See also Australia, Commanders’ Guide (1994), §§ 919 and 920, ibid, § 937; New Zealand, Military Manual (1992), § 507, ibid, § 949; UK, Military Manual (1958), §§ 115–116, ibid, § 957; US Field Manual 27-10 (1956), § 31, ibid, § 959; US Air Force Pamphlet (1976), § 8-6(d), ibid, § 960.

34  Canada, LOAC Manual (1999), p. 6-3, §§ 25–7, cited in: Henckaerts/Doswald-Beck, Customary IHL, Vol. II, Chapter 18, § 940; Australia, Defence Force Manual (1994), §§ 724 and 725, ibid, § 936; Australia, Commanders’ Guide (1994), §§ 919 and 920, ibid, § 937; UK, Military Manual (1958), §§ 115–116, ibid, § 957; US Field Manual 27-10 (1956), § 31, ibid, § 959; US Air Force Pamphlet (1976), § 8-6(d), ibid, § 960.

35  For an overview of the historical discussion on assassination between the 13th and 18th centuries see Schmitt, State-Sponsored Assassination, pp. 613 ff.; Zengel, Assassination and the Law of Armed Conflict, pp. 125 ff.; Watkin, Humans in the Cross-Hairs, pp. 169 ff.

36  Unconvinced and critical with regard to a definition of assassination based on historical precepts also Reisman, Reflections on Assassination and the Schmitt Formula, pp. 689.

37  Schmitt, State-Sponsored Assassination, pp. 683 f.; Watkin, Humans in the Cross-Hairs, pp. 169 ff.; Zengel, Assassination and the Law of Armed Conflict, p. 125.

38  Schmitt, State-Sponsored Assassination, pp. 621, 645 ff.; Parks, Memorandum EO 12333. p. 7; Scharf, Enforcing the International Ban on Biological and Chemical Weapons, p. 497; Harder, Time to Repeal the Assassination Ban, pp. 10, 19; Turner, It’s Not Really ‘Assassination’, p. 799; Beres, Assassinating Saddam Hussein, pp. 847 ff.; Beres, American Doctrine of Preemption, pp. 160 f.; Kremnitzer, Preventive Killings, p. 3; Tomuschat, Gezielte Tötungen, pp. 138 f.; Gross, Democracy in the War against Terrorism, pp. 1194 ff.; Downes, ‘Targeted Killings’ in an Age of Terror, pp. 286 f.; Kendall, ‘Targeted Killings’ Under International Law, pp. 1078 ff.

39  Downes, ‘Targeted Killings’ in an Age of Terror, pp. 280 f.; O’Connell, To Kill or Capture Suspects, pp. 328 ff.; Ruys, License to Kill?, pp. 22 f.

40  Downes, ‘Targeted Killings’ in an Age of Terror, pp. 286 f.; Pickard, Legalizing Assassination?, pp. 10 ff. See also Slaughter, Mercy Killings, pp. 1 f., who proposes that the UN Security Council should issue international ‘death warrants’ against dictators such as Iraqi President Saddam Hussein.

41  Brief remarks were made by Heymann/Kayyem, Long-Term Legal Strategy, p. 68, who contend that, even with consent of the territorial State, a targeted killing would be permissible only where it additionally meets a three-pronged test of ‘necessity’, ‘reasonable imminence’, and ‘preventative motivation’.

42  Brief remarks were made by Downes, ‘Targeted Killings’ in an Age of Terror, pp. 286 f., who argues that UN Security Council Resolution 1373 (28 September 2001), which authorizes States to take ‘the necessary steps to prevent the commission of terrorist acts’, cannot be interpreted to authorize the use of interstate force and, in particular, targeted killings on a continuous basis.

43  See, Gross, Democracy in the War against Terrorism, pp. 1196 ff.; Turner, It’s Not Really ‘Assassination’, pp. 787 ff. This approach is criticized by Ruys, License to Kill?, pp. 22 f.

44  See, Downes, ‘Targeted Killings’ in an Age of Terror, pp. 280 f., who argues that, in the absence of a situation of armed conflict, a State carrying out a targeted killing with the consent of the territorial State must respect the standards of law enforcement. See further: O’Connell, To Kill or Capture Suspects, pp. 328 ff.; Tomuschat, Gezielte Tötungen, pp. 138 f.; Schmitt, State-Sponsored Assassination, p. 645; Addicott, Proposal for a New Executive Order, p. 782.

45  See Slaughter, Mercy Killings, pp. 1 f. and, as a whole, Beres, Assassinating Saddam Hussein.

46  In the case of Israel, there are serious doubts as to the relevance of the right of interstate self-defence for the justification of its policy of targeted killing. As an occupying power, Israel by definition has effective control over the occupied territories in which its targeted killings are carried out. Therefore, the ICJ held that Israel could not base its security measures in the occupied territories on Art 51 UN Charter (ICJ, Legal Consequences of a Wall Opinion, § 139). See also PCATI/LAW, Assassination Policy of Israel, pp. 91 ff.; Nolte, Weg in eine andere Rechtsordnung, pp. 8 ff. Apparently undecided: Tomuschat, Gezielte Tötungen, pp. 138 f. Affirming the relevance of Israel’s right of self-defence: Kendall, ‘Targeted Killings’ Under International Law, p. 1088; Gross, Democracy in the War against Terrorism, pp. 1194 ff.

47  Kremnitzer, Preventive Killings, pp. 12 f.; Kendall, ‘Targeted Killings’ Under International Law, p. 1078; Gross, Democracy in the War against Terrorism, pp. 1194 ff. Gross further argues that non-State terrorism may also amount to ‘indirect aggression’ by a host State.

48  Parks, Memorandum EO 12333 EO 12333, pp. 7 f.; Schmitt, State-Sponsored Assassination, pp. 646 ff.; Addicott, Proposal for a New Executive Order, pp. 772 ff.; Solis, Assassination and American Armed Forces, pp. 7 f.; Kremnitzer, Preventive Killings, pp. 12 ff. and 14 f.

49  Downes, ‘Targeted Killings’ in an Age of Terror, pp. 287 ff., Kendall, ‘Targeted Killings’ Under International Law, pp. 1079 ff.; Gross, Democracy in the War against Terrorism, pp. 1196 ff.; PCATI/ LAW, Assassination Policy of Israel, p. 92; Kremnitzer, Preventive Killings, p. 13.

50  See Beres, American Doctrine of Preemption, p. 165; Gross, Democracy in the War against Terrorism, pp. 1196 ff.; Kendall, ‘Targeted Killings’ Under International Law, pp. 1079 ff.

51  Parks, Memorandum EO 12333, p. 8; Harder, Time to Repeal the Assassination Ban, pp. 19 ff., 34; Schmitt, State-Sponsored Assassination, pp. 644 ff.; Harder, Time to Repeal the Assassination Ban, p. 34; Turner, It’s Not Really ‘Assassination’, pp. 799 ff., 803 f.; Addicott, Proposal for a New Executive Order, pp. 769 ff., 774 ff.; Solis, Assassination and American Armed Forces, pp. 7 f.; Ulrich, The Gloves Were Never On, p. 1050; Pickard, Legalizing Assassination?, pp. 21, 27; Raines, Just War Doctrine and Targeted Killings, p. 238; Beres, Assassinating Saddam Hussein, pp. 847 ff. See also Beres, American Doctrine of Preemption, pp. 160 ff.; 164 ff., who uses the rather confusing title ‘Assassination as Law Enforcement among States not at War’ for his section on anticipatory self-defence.

52  See, for example, Nolte, Moves into a Different Legal Order, pp. 116 ff.; Downes, ‘Targeted Killings’ in an Age of Terror, pp. 287 f.; PCATI/LAW, Assassination Policy of Israel, p. 92.

53  For an analysis leading to the opposite conclusion, see Dinstein, War, Aggression and Self-Defence, pp. 297 ff.

54  Scharf, Enforcing the International Ban on Biological and Chemical Weapons, pp. 498 f.; Heymann/Kayyem, Long-Term Legal Strategy, pp. 60, 67; Ulrich, The Gloves Were Never On, pp. 1057 f.

55  Scharf, Enforcing the International Ban on Biological and Chemical Weapons, n. 111, referring to Model Penal Code, Section 3.02 (1985).

56  Heymann/Kayyem, Long-Term Legal Strategy, p. 68. See also the discussion of the standards proposed by Heymann/Kayyem below, III.5.6., pp. 67 ff.

57  Heymann/Kayyem, Long-Term Legal Strategy, p. 68.

58  For the legal premises pertaining to the law of interstate force on which this analysis is based, see below IV.2.1., pp. 74 f.

59  The rules of international armed conflict are applied, for example, by: Cassese, Expert Opinion on Israel’s Targeted Killings, pp. 2 ff.; Ruys, License to Kill?, pp. 32 f.; Amnesty International, Israel Must End its Policy of Assassinations, pp. 2 f. The rules of non-international armed conflict are applied, for example, by: Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, pp. 258 f.; Nolte, Weg in eine andere Rechtsordnung, pp. 8 ff. and, by implication, David, Fatal Choices, p. 15. Contra qualification as an ‘armed conflict’: Tomuschat, Gezielte Tötungen, pp. 137 f. and, by implication, B’Tselem, Israel’s Assassination Policy, pp. 6 ff.

60  Provided sufficient intensity, pro qualification as a non-international armed conflict: Kremnitzer, Preventive Killings, p. 4 f.; Kretzmer, Targeted Killing of Suspected Terrorists, pp. 201 ff.; Ruys, License to Kill?, p. 30. Subject to the law of armed conflict only in ‘designated zones of active combat’: Heymann/Kayyem, Long-Term Legal Strategy, pp. 64 ff. May also be part of an international armed conflict: Ruys, License to Kill?, p. 30. Apparently undecided: Downes, ‘Targeted Killings’ in an Age of Terror, pp. 281 ff., 294.

61  Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, pp. 262 ff., 289 f.; PCATI/LAW, Assassination Policy of Israel, pp. 85 f.; Tomuschat, Gezielte Tötungen, p. 140; Amnesty International, Israel Must End its Policy of Assassinations, pp. 2 ff.; Nolte, Weg in eine andere Rechtsordnung, pp. 8 ff.

62  Amnesty International, Israel Must End its Policy of Assassinations, pp. 2 ff.; PCATI/LAW, Assassination Policy of Israel, pp. 86 ff.; Tomuschat, Gezielte Tötungen, p. 140; Ruys, License to Kill?, p. 35; Kremnitzer, Preventive Killings, p. 10; Nolte, Weg in eine andere Rechtsordnung, pp. 8 ff.

63  Tomuschat, Gezielte Tötungen, pp. 139 f.; Watkin, Canada/US Interoperability pp. 309 f.; Kremnitzer, Preventive Killings, pp. 4 ff.; Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, pp. 278 ff.; Ruys, License to Kill?, pp. 27 ff.; Watkin, Humans in the Cross-Hairs, p. 139; Addicott, Proposal for a New Executive Order, pp. 782 f.

64  Watkin, Humans in the Cross-Hairs, pp. 145 ff., 160 ff.; PCATI/LAW, Assassination Policy of Israel, pp. 90 f.; Cassese, Expert Opinion on Israel’s Targeted Killings, pp. 2 ff., Downes, ‘Targeted Killings’ in an Age of Terror, pp. 281 ff.; Tomuschat, Gezielte Tötungen, pp. 139 f.; Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, pp. 265 ff.; Watkin, Canada/US Interoperability, pp. 311 ff.; Ruys, License to Kill?, p. 28; Kremnitzer, Preventive Killings, pp. 5 f.; Kelly, Assassination in War Time, p. 110; Parks, Memorandum EO 12333, p. 7; Addicott, Proposal for a New Executive Order, p. 783.

65  Watkin, Humans in the Cross-Hairs, pp. 153 ff.; Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, pp. 278 f.; Cassese, Expert Opinion on Israel’s Targeted Killings, pp. 5 ff.; PCATI/LAW, Assassination Policy of Israel, pp. 86 ff.; Nolte, Weg in eine andere Rechtsordnung, pp. 8 ff.; Ruys, License to Kill?, pp. 28 ff.; Tomuschat, Gezielte Tötungen, pp. 139 f.; Kelly, Assassination in War Time, p. 110; Parks, Memorandum EO 12333, p. 6.

66  See, for example, David, Fatal Choices, p. 15. Criticized also by Downes, ‘Targeted Killings’ in an Age of Terror, pp. 281 ff.; Nolte, Weg in eine andere Rechtsordnung, pp. 8 ff. As rightly stated by Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, p. 270, on the lawfulness of targeted killings under IHL, ‘the debate over whether an act of violence [i.e. of the targeted person] is a deplorable act of terrorism, or a laudable manifestation of heroism, is immaterial’.

67  Schmitt, State-Sponsored Assassination, pp. 640 f., 644; Harder, Time to Repeal the Assassination Ban, p. 8, n. 37; Wedgwood, Legality of Targeted Assassinations, p. 4; Addicott, Proposal for a New Executive Order, p. 782, n. 210; Tomuschat, Gezielte Tötungen, p. 136. Some authors discuss military necessity as an aspect of the principle of proportionality. Thus, with regard to the permissibility of direct attacks against civilians preparing to take a direct part in the hostilities or returning from combat, Ben-Naftali/Michaeli contend that ‘[t]he proportionality principle imposes a duty to evaluate the military need in such action against the availability of other means in the particular circumstances’ (Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, p. 279).

68  See, for example, Pickard, Legalizing Assassination?, p. 18.

69  Kelly, Assassination in War Time, pp. 101 f.; Parks, Memorandum EO 12333, p. 4; Schmitt, State-Sponsored Assassination, pp. 633 ff.; Zengel, Assassination and the Law of Armed Conflict, p. 131; David, Fatal Choices, pp. 15 f.; Kendall, ‘Targeted Killings’ Under International Law, pp. 1076 ff., 1088; Kremnitzer, Preventive Killings, pp. 3 f.; Ruys, License to Kill?, pp. 23 ff., pp. 35 f.; Harder, Time to Repeal the Assassination Ban, p. 35 f.

70  Kelly, Assassination in War Time, p. 104; Parks, Memorandum EO 12333, pp. 5 f.; Schmitt, State-Sponsored Assassination, pp. 635 ff.; David, Fatal Choices, pp. 16; Kendall, ‘Targeted Killings’ Under International Law, p. 1077; Ruys, License to Kill?, p. 35; Zengel, Assassination and the Law of Armed Conflict, pp. 132 ff.

71  B’Tselem, Israel’s Assassination Policy, pp. 8 ff.; Proulx, Indefinite Detention and Targeted Killing, p. 888; Kremnitzer, Preventive Killings, pp. 7, 8 ff.

72  Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, pp. 250, 277 f.; PCATI/ LAW, Assassination Policy of Israel, p. 91; B’Tselem, Israel’s Assassination Policy, pp. 8 ff.; Amnesty International, Israel Must End its Policy of Assassinations, pp. 5 f.; Proulx, Indefinite Detention and Targeted Killing, p. 888; Downes, ‘Targeted Killings’ in an Age of Terror, pp. 281 ff.; Kremnitzer, Preventive Killings, pp. 8 ff.; Ruys, License to Kill?, p. 36.

73  See below, Chapters VII; X–XII; XIV.

74  Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, p. 253; Kremnitzer, Preventive Killings, p. 1.

75  Nolte, Weg in eine andere Rechtsordnung, pp. 8 ff.; Tomuschat, Gezielte Tötungen, p. 137; Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, p. 264.

76  Kremnitzer, Preventive Killings, pp. 2 f.

77  Kretzmer, Targeted Killing of Suspected Terrorists, pp. 184 f.; Kremnitzer, Preventive Killings, p. 14.

78  Kretzmer, Targeted Killing of Suspected Terrorists, pp. 183, 203; Kremnitzer, Preventive Killings, pp. 6 f.

79  Kretzmer, Targeted Killing of Suspected Terrorists, p. 182; Kremnitzer, Preventive Killings, p. 14.

80  Amnesty International, Israel Must End its Policy of Assassinations, pp. 2 ff.; PCATI/LAW, Assassination Policy of Israel, pp. 86 ff.; Tomuschat, Gezielte Tötungen, p. 140; Ruys, License to Kill?, p. 35; Kremnitzer, Preventive Killings, p. 10; Nolte, Weg in eine andere Rechtsordnung, pp. 8 ff.

81  See PCATI/LAW, Assassination Policy of Israel, pp. 68 ff.; Ruys, License to Kill?, pp. 16 ff.; Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, pp. 284 ff.

82  Ruys, License to Kill?, pp. 20 f.

83  Ibid, pp. 20 f.; PCATI/LAW, Assassination Policy of Israel, p. 77.

84  Amnesty International, Israel Must End its Policy of Assassinations, p. 2; PCATI/LAW, Assassination Policy of Israel, p. 78; Nolte, Weg in eine andere Rechtsordnung, pp. 8 ff.; Ben-Naftali / Michaeli, ‘We Must Not Make a Scarecrow of the Law’, p. 286; Kremnitzer, Preventive Killings, p. 2.

85  Kremnitzer, Preventive Killings, p. 2.

86  Ben-Naftali / Michaeli, ‘We Must Not Make a Scarecrow of the Law’, pp. 286 f.; Kremnitzer, Preventive Killings, p. 2; Ruys, License to Kill?, pp. 20 f.

87  Kremnitzer, Preventive Killings, p. 2.

88  Ibid.

89  Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, pp. 286 f.; Ruys, License to Kill?, pp. 20 f.; Kremnitzer, Preventive Killings, p. 2; Amnesty International, Israel Must End its Policy of Assassinations, pp. 2, 6; PCATI/LAW, Assassination Policy of Israel, p. 78.

90  Tomuschat, Gezielte Tötungen, p. 140; Kremnitzer, Preventive Killings, p. 1; Amnesty International, Israel Must End its Policy of Assassinations, p. 3

91  PCATI/LAW, Assassination Policy of Israel, p. 80; Tomuschat, Gezielte Tötungen, p. 140.

92  B’Tselem, Israel’s Assassination Policy, p. 8; 12; Nolte, Weg in eine andere Rechtsordnung, pp. 8 ff.

93  B’Tselem, Israel’s Assassination Policy, p. 8; 12.; PCATI/LAW, Assassination Policy of Israel, pp. 78 ff., 80; Kremnitzer, Preventive Killings, p. 1; Tomuschat, Gezielte Tötungen, p. 140; Proulx, Indefinite Detention and Targeted Killing, p. 888.

94  See below, Chapters VI; VIII; IX; XIII.

95  Ben-Naftali/Michaeli, ‘We Must Not Make a Scarecrow of the Law’, pp. 287 ff.

96  Ibid, pp. 287, 291.

97  Ibid, p. 290.

98  Ibid, pp. 287, 291.

99  Ibid, p. 291.

100  Ibid, p. 289.

101  The expert opinion was submitted by the petitioners in the case Israel HCJ, PCATI v Israel (see above, II.4.3.(a), pp. 32 ff.).

102  Cassese, Expert Opinion on Israel’s Targeted Killings, p. 20.

103  Ibid, p. 7.

104  Ibid, p. 9.

105  Ibid, pp. 9 f., 19 f. Cassesse refers to the McCann Case (see Appendix, Case No. 1).

106  Kremnitzer, Preventive Killings, p. 2.

107  Ibid, pp. 2 f.

108  Ibid, p. 14.

109  Ibid, pp. 13 f.

110  Ibid, pp. 6 f.

111  Ibid, pp. 4 f.

112  Ibid, p. 4.

113  Ibid, pp. 4 ff.

114  Ibid, pp. 8 ff.

115  Ibid, pp. 7 f.

116  Ruys, License to Kill?, pp. 20 f.

117  Ibid, pp. 20 f.

118  Ibid, p. 21.

119  Ibid, p. 37, referring to: Report of the Special Rapporteur on extrajudicial, summary or arbitrary executions, 25 January 1996, UN Doc. E/CN.4/1996/4.

120  Ibid, pp. 25, 35.

121  Ibid, pp. 27 ff., 39.

122  Ibid, p. 35.

123  Ibid, pp. 22 f., 30, 34 f.

124  Ibid, p. 36.

125  Ibid, p. 39.

126  Ibid, p. 39.

127  Ibid, p. 39.

128  Kretzmer, Targeted Killing of Suspected Terrorists, p. 176.

129  Ibid, pp. 186 f., 189 ff.

130  Ibid, pp. 174, n. 16, 176 and 206.

131  Ibid, pp. 175, 201, 203.

132  Ibid, p. 193.

133  Ibid, p. 198.

134  Ibid, pp. 201 f.

135  Ibid, pp. 175, 201 ff.

136  Ibid, p. 203. Although less relevant for the substantive permissibility of targeted killings, Kretzmer also proposes to incorporate the standards of investigation required under human rights law into the ‘mixed model’ (ibid, p. 204).

137  Ibid, p. 203.

138  Ibid, pp. 203 f.

139  Ibid, p. 204.

140  Ibid, p. 203.

141  Heymann/Kayyem, Long-Term Legal Strategy, p. 63.

142  Ibid, p. 63.

143  Ibid, p. 65.

144  Ibid, p. 59.

145  Ibid, pp. 65, 67.

146  Ibid, p. 59.

147  Ibid, p. 5. The authors deem it indispensable and appropriate to add that the resort to targeted killings would in no case be justified against a US citizen, or within the United States or another State capable and willing to cooperate with US counter-terrorism efforts.

148  Ibid, pp. 59 f.

149  Ibid, p. 67.

150  Ibid, p. 68.

151  Ibid, p. 68.

152  Ibid, p. 67.

153  See also above, III., nn. 54 ff. and accompanying text.