1  Recently a number of criticisms have been addressed to international courts and tribunals, irrespective of whether they are universal or regional, permanent or ad hoc, or general or specialized. The following are only a few examples of such criticisms.

2  In Vienna Convention on Consular Relations, the International Court of Justice (ICJ) indicated in the provisional measures that the United States (‘US’) should take all measures at its disposal to ensure that Angel Breard was not executed pending the final decision (Vienna Convention on Consular Relations, Paraguay v United States, 1998, para 41 (‘Breard’)). In response, the Governor of Virginia issued a press statement:

I am concerned that to delay Mr. Breard’s execution so that the International Court of Justice may review this matter would have the practical effect of transferring responsibility from the courts of the Commonwealth and the United States to the International Court … Indeed, the safety of those residing in the Commonwealth of Virginia is not the responsibility of the International Court of Justice. It is my responsibility and the responsibility of law enforcement and judicial officials throughout the Commonwealth. I cannot cede such responsibility to the International Court of Justice (Gilmore, 1998, 317–18).

3  Following a series of judgments, such as Hirst v United Kingdom (2005), rendered by the European Court of Human Rights (ECtHR) finding that the blanket ban on the right of a convicted prisoner to vote imposed by United Kingdom (‘UK’) law constituted a violation of Article 3 Protocol No 1 to the Convention on the Protection of Human Rights and Fundamental Freedoms (right to free elections), the UK House of Commons adopted a resolution declaring: ‘this House … is the opinion that legislative decisions of this nature should be a matter for democratically-elected lawmakers’ (Hansard, 2011, column 585–86).

4  In 2016, the tribunal in South China Sea (Republic of the Philippines and People’s Republic of China) (‘South China Sea’) rendered an award finding that China had violated various international obligations in relation to the Philippines. In a press conference held on the following day, the Vice Foreign Minister of China stated:

5  Discussions on the legitimacy of international adjudication are particularly relevant at a time when a certain number of States threaten to and actually do withdraw from international adjudication (Pauwelyn and Hamilton, 2018, 681–83; McLachlan, 2019, 503–11).

6  It is generally considered that the term ‘legitimacy’ is meant to refer to the justification of the exercise of public authority (Legitimacy in International Law). There are at least two types of legitimacy. While normative or prescriptive legitimacy is evaluated from an objective point of view in light of certain predetermined standards, sociological or descriptive legitimacy derives from perceptions or beliefs that the public authority in question has such justification (Grossman, 2017, 4). Although conceptually different, they are frequently, if not always, intertwined (Bodansky, 2013, 327). Sociological legitimacy may be dependent upon normative legitimacy as actors of a given society may believe that certain exercise of public authority is legitimate (or not) in light of certain standards of normative legitimacy that they accept or internalize. On the other hand, the relevance of standards of normative legitimacy is proportionate to the degree of their acceptance in a given society: a standard of what is claimed to be normative legitimacy is of no practical relevance if it is not at all accepted in that society.

7  The present entry deals with normative legitimacy. The importance of sociological legitimacy should not be underestimated as it has motivating force for compliance (Follesdal, 2020, 480). However, it can only be assessed empirically by opinion survey or discourse analysis (Bodansky, 2013, 332–36) and very little research work has carried out such assessment; what does exist, primarily concerns European courts (Voeten, 2013; Çalı and others, 2013; Pollack, 2018, 162–72).

8  Authority may be legitimated by its source of origin, the procedure in which its decisions are taken, or by the outcome that it produces (Wolfrum, 2008, 6–7)

9  Since States are sovereign, the power of international courts and tribunals that render decisions binding upon them needs to be based on their consent. In addition, it also needs to be democratically justified, at least when such decisions legally affect individuals in one way or another.

10  ‘The jurisdiction of the Court comprises all cases which the parties refer to it’ (Art 36 (1) Statute of the International Court of Justice (1945) (‘ICJ Statute’)). In other words, ‘[the Court’s] jurisdiction is based on the consent of the parties and is confined to the extent accepted by them’ (Armed Activities on the Territory of the Congo (New Application: 2002), Democratic Republic of the Congo v Rwanda, 2006, 39, para 88). This ‘fundamental principle of consent’ (Application of the International Convention on the Elimination of All Forms of Racial Discrimination, Georgia v Russian Federation, 2011, para 131) applies to all international courts and tribunals (Consent).

11  It follows that a decision of a court rendered beyond ‘the extent accepted by’ the disputing parties is ultra vires and therefore null and void. Thus the US argued in the United Nations Security Council (‘UNSC’), where the draft resolution calling for full and immediate compliance with the Nicaragua judgment (Military and Paramilitary Activities in and against Nicaragua, Nicaragua v United States of America, 1986, 14 (‘Nicaragua’)) was examined, that ‘no Court, not even the International Court of Justice, has the legal power to assert jurisdiction where no basis exists for that jurisdiction’ (UNSC Provisional Verbatim Record, 1986, 46). Likewise, with respect to the South China Sea arbitration, China stated that ‘the tribunal itself is not given the absolute right to determine whether it has the jurisdiction or not’ (Ambassador Liu, 2016). In its judgment of 12 October 1993 (‘Maastricht judgment’), the German Constitutional Court warned that whenever the European Union (‘EU’)/European Communities (‘EC’) organs, including the then Court of Justice of the European Communities (‘CJEC’), interpreted and applied the EU treaties and secondary laws beyond the scope of the consent given by Germany, German State organs would be constitutionally prohibited from recognizing or implementing EU/EC laws as interpreted by EU/EC organs (Maastricht, Bundesverfassunggericht, 1993, 188).

12  However, from a strictly legal point of view, such an argument is without merit since ‘[i]n the event of a dispute as to whether the Court has jurisdiction, the matter shall be settled by the decision of the Court’ (Art 36 (6) ICJ Statute). The Kompetenz-Kompetenz, compétence de la compétence or Competence-Competence, which ‘[t]he Court always possesses’ (Application of the Convention on the Prevention and Punishment of the Crime of Genocide, Croatia v Serbia, 2008, para 86) is also considered to be a fundamental principle, without which no court or tribunal could function in a meaningful way. The compétence de la compétence, combined with the lack of instance of review—except with respect to investment arbitration—makes it practically impossible for any frustrated disputing party to see the decision in question rendered null and void. Thus, the disputed decision remains legally valid and binding upon the parties.

13  On the other hand, a different argument can be made from the legitimacy perspective. Whether or not it is bound by the judgment of the ICJ, it is clear that the US considers that the Nicaragua judgment lacks legitimacy because it goes beyond ‘the extent accepted by’ the US. The same applies to China’s position in the South China Sea arbitration or to the Maastricht judgment of the German Constitutional Court.

14  A similar argument was advanced by the US with respect to the World Trade Organization (‘WTO’) dispute settlement system. The US raised its concern that the Appellate Body disregards the rules as agreed by the WTO Members by adding to or diminishing rights and obligations under the WTO Agreements, issuing obiter dicta, or claiming that reports are entitled to be treated as precedent (Office of the United States Trade Representative, 2018 22–28). In other words, the WTO Appellate Body acts, at least from the US perspective, beyond the consent given by WTO Members (Appellate Body: Dispute Settlement System of the World Trade Organization (WTO)).

15  The democratic (il)legitimacy of the judiciary in the domestic legal order is a classic question: how is it possible for non-elected judges to reverse, modify, or annul measures taken by the democratically elected parliament (Ely, 1980; Brondel and others, 2001)? A similar argument can be made with respect to international courts and tribunals, particularly in cases where the latter call into question domestic measures taken by the respondent State, as in the Breard case or in Hirst v United Kingdom. For that reason, human rights courts (Zorkin, 2016, 12; Leach and Donald, 2016, 115–19; Saul and others, 2017, 2–8; Breuer, 2019, 16–19; for human rights treaty bodies, Hamamoto, 2007, 200), the WTO dispute settlement system (Fukunaga, 2008, 97–100), investment arbitral tribunals (Public Citizen, 2005, 2), and the CJEC (now the Court of Justice of the European Union (‘CJEU’)) (Rasmussen, 1986, 8–9) have frequently been criticized for being anti-democratic.

16  In the domestic legal order, the democratic illegitimacy of the court is mitigated by the legislature: if not satisfied with a decision rendered by the court affecting a piece of legislation, a legislature may adopt new amend existing legislation. In the international legal order however, such ex post control of the judiciary by the legislature is not to be expected given the lack of such possibility (Higuchi, 2002, 37). More fundamentally, if democracy is understood to be a form of government by the whole population grouped in a State, international courts and tribunals are bound to be undemocratic since they are not based on the will of a single State but on agreements between several States and apply international law, which does not derive from the population of a single State. It follows that the ‘demos’ needs to be differently conceived if one requires international courts and tribunals themselves to be democratically legitimate (Bogdandy and Venzke, 2014, 214; Follesdal, 2018, 311–13).

17  From a more moderate perspective it is possible to see that international courts and tribunals function in conformity with democratic principles, as long as they take certain measures. For example, human rights courts often take into account the quality of the domestic democratic process through which the domestic measures in question are adopted when appreciating the proportionality of such measures (Lazarus and Simonsen, 2015). In VgT Verein Gegen Tierfabriken v Switzerland, the ECtHR found that the application of Swiss legislation prohibiting ‘political advertising’ to a television commercial against meat consumption constituted a violation of Article 10 ECHR (freedom of expression) on the ground that it could not be considered as ‘necessary in a democratic society’ (VgT Verein Gegen Tierfabriken v Switzerland, 2001, paras 74–79). Twelve years later, in an essentially identical case, the ECtHR refused to find a violation of Article 10, taking into account ‘[t]he quality of the parliamentary and judicial review of the necessity of the measure’ (Animal Defenders International v United Kingdom, 2013, para 108). According to the Court, ‘[t]he prohibition was … the culmination of an exceptional examination by parliamentary bodies of the cultural, political and legal aspects of the prohibition’, which included an ‘examin[ation] in detail [of] the impact of [the VgT] judgment’ (Animal Defenders International v United Kingdom, para 114).

18  Some international courts and tribunals have started to accept views submitted by non-disputing non-State parties. In the WTO, the Appellate Body has found that panels as well as the Appellate Body itself have the ‘authority’—not an obligation—to accept and consider amicus curiae briefs (International Courts and Tribunals, Amicus Curiae; Amicus Curiae: Dispute Settlement System of the World Trade Organization (WTO)) submitted by non-governmental organizations (‘NGOs’) on the basis of their power to undertake and control the dispute settlement process (US – Shrimp, Appellate Body Report, paras 106, 110; US – Lead and Bismuth II, Appellate Body Report, para 39). It is often considered that such acceptance and consideration of amicus curiae briefs contributes to the enhancement of democratic legitimacy of the WTO dispute settlement procedure (Keller, 2005, 459).

19  Recent EU trade agreements also allow non-governmental third parties established in a party to the agreement to submit amicus curiae briefs (eg Art 14.15 Free trade Agreement between the European Union and its Member States, of the one part, and the Republic of Korea, of the other part (‘EU-Korea FTA’); Art 319 Association Agreement between the European Union and its Member States, of the one part, and Ukraine, of the other part (‘EU-Ukraine Association Agreement’)). In 2019 and 2020, panels respectively constituted pursuant to the EU-Korea FTA and the EU-Ukraine Association Agreement took dispositions for the submission of amicus curiae briefs (European Commission, 2019; European Commission, 2020).

20  Similar developments can be observed in investment arbitration (Amicus Curiae: Investment Arbitration). North American Free Trade Association tribunals started to accept amicus curiae briefs in 2001 and some of recent investment treaties explicitly grant the arbitral tribunals to be established under them to accept and consider such briefs. Most notably the United Nations Commission on International Trade Law (‘UNCITRAL’) adopted the Rules on Transparency in Treaty-based Investor-State Arbitration (2013) and the United Nations Convention on Transparency in Treaty-based Investor-State Arbitration (2014). These developments are also seen as enhancing the democratic legitimacy of investor-State dispute settlement.

21  On the other hand it has also been pointed out that allowing non-disputing non-State parties to submit views merely covers occasional demos (Fontanelli and Busco, 2016, 7). While accepting such amicus curiae briefs may contribute to the enhancement of the democratic legitimacy of the system in the Global North, where resource-rich NGOs exist, it may have adverse effects in the Global South (Stewart, 2014, 263; Uruena Hernandez, 2016, 400–401). It is true that most of the amicus briefs submitted to WTO panels and the Appellate Body come from the Global North (Charwat, 2016, 21–23).

22  The democratic legitimacy of international criminal tribunals is often discussed from a similar but different point of view. It is argued that the International Criminal Tribunal for the Former Yugoslavia (ICTY) and the International Criminal Tribunal for Rwanda (ICTR) are not democratically legitimate as they were established by UNSC resolutions (Drumbl, 2007, 133) and that the International Criminal Court (ICC) is not democratically legitimate where it exercises jurisdiction over defendants whose States of nationality are not parties to the Rome Statute and have not otherwise consented to jurisdiction (Morris, 2002, 592). In 2020 when the ICC Appeals Chamber issued a decision that authorized an investigation into the situation in Afghanistan (Judgment on the appeal against the decision on the authorisation of an investigation into the situation in the Islamic Republic of Afghanistan, 2020), the US Secretary of State declared that ‘this [wa]s a truly breathtaking action by an unaccountable political institution masquerading as a legal body’ (Pompeo, 2020). However, it had already been stated that the court does not have to be institutionally democratic to be legitimate; it must simply protect the rights of citizens in a normatively appropriate way (Fichtelberg, 2006, 775; Glasius, 2012, 63).

23  The legitimacy of international courts and tribunals can be examined from a procedural perspective, as far as their composition and decision-making process is concerned (Wolfrum, 2008, 6).

24  Article 9 ICJ Statute, which refers to ‘the representation of the main forms of civilization and of the principal legal systems of the world’ on the bench, guarantees equitable geographical distribution to a certain extent. A similar provision is found in the Statute of the International Tribunal for the Law of the Sea (ITLOS) (Arts 2 (2) and 3 (2)), the WTO Dispute Settlement Understanding (‘DSU’) (Art 17 (3)) and the Rome Statute (Art 36 (8) (a)).

25  When the legitimacy of the ICJ was seriously questioned by a number of developing States following the South West Africa judgments in 1966 (South West Africa, Ethiopia v South Africa; Liberia v South Africa, 1966, 6), the composition of the court was considered to be unjustifiably favourable to developed States, particularly to the permanent members of the UNSC (Official Records of the UNGA Sixth Committee, 1281st meeting, 1971, para 60 (Tanzania); Official Records of the UNGA Sixth Committee, 1284th meeting, 1971, para 19 (Guyana)). Since then the geographical distribution of judges has evolved and there seems to be no strong voice questioning the legitimacy of the ICJ in terms of geographical diversity. Although nationals of specific States—the five Permanent Members (‘P5’) and some other ‘big ones’—tend to be elected and re-elected (Keith, 2017, 147), the convention that the P5 were de facto entitled to representation on the ICJ was broken in 2017, when one additional seat was allocated to the Asian group to the detriment of the group of Western European and other States (Fassbender, 2019, para 20).

26  The imbalance in the composition of adjudicators in the International Military Tribunals, who were all appointed by victorious States (Arts 1 and 2 Charter of the International Military Tribunal at Nuremberg (IMT); Art 2 Charter of the International Military Tribunal for the Far East (IMTFE)), has often been referred to by those who question the legitimacy of these tribunals, which are perceived as having rendered ‘victors’ justice’ (Minear, 1972, 74–86; May and Fyfe, 2017, 28–30). In later international criminal tribunals, equitable geographical distribution is taken into account when judges are elected (Art 13ter (1) (c) ICTY Statute; Art 12ter (1) (c) ICTR Statute, Art 36 (8) (a) Rome Statute; Election of Judges: International Criminal Court (ICC)).

27  However geographical imbalance has become a subject of critical debates with respect to investment arbitration tribunals, whose arbitrators are appointed by disputing parties and appointing authorities who are under no obligation to take into account equitable geographical representation (Geopolitical Representativeness in International Adjudicatory Bodies). According to the International Centre for Settlement of Investment Disputes (ICSID), 67% of the arbitrators, conciliators, and ad hoc committee members appointed in cases for the period ending 30 June 2020 are from Western Europe and North America, while only 12% of the disputes come from these regions (ICSID, 2020, 12, 17).

28  As for gender diversity, the imbalance is patent in many international courts and tribunals (eg three women out of 15 at the ICJ or four out of 21 at the ITLOS) although it has been gradually rectified in some, whose constitutive documents or relevant instruments oblige member States to take gender balance into account when electing judges (Art 36 (8) (a) (iii) Rome Statute; Art 12 Protocol to the African Charter on Human and Peoples’ Rights on the Establishment of an African Court on Human and Peoples’ Rights; Parliamentary Assembly of the Council of Europe, Resolution 1841 (2011), para 6.3) (Gender Balance in International Adjudicatory Bodies).

29  Diversity is a complex concept as it contains a number of parameters. Geographical representation and gender balance, mentioned above, are the most evident ones but diversity can include broader considerations such as age, ethnicity, language, legal background, as well as the country of origin, reflecting the different stages of economic development (UNCITRAL Report of Working Group III, Oct–Nov 2018, para 92; Representation of Cultural Diversity in International Adjudicatory Bodies). It is also not always easy to explain the relevance of diversity. It is true that geographical diversity may well be required in light of sovereign equality. However, although it is often argued that diversity on the bench will bring insight and sensitivity to judicial deliberation that would otherwise be absent from the decision-making process (Sellers, 2018, 350), it is difficult to base such an argument on empirical data. For example, there are no empirical studies that indicate that female judges decide cases differently from male judges (Boyd and others, 2010) and, rather paradoxically, the mere presence of a non-Western arbitrator is positively correlated with claimant success in investor-State arbitration (Langford and others, 2018, 19). Diversity on the bench is thus required because it is considered to be a desirable objective in and of itself (Kaufmann-Kohler and Potestà, 2017, para 46).

30  Independence relates to the ability of courts and tribunals to deliberate and reach decisions in light of the law and without any undue external pressure or influence. Impartiality requires that adjudicators are able to act as neutral arbiters without interests or ideological preferences that would bias them in favour of a disputing party (Squatrito, 2018, 406) (Independence: International Adjudication).

31  Independence and impartiality of adjudicators are key elements of any system of justice (UNCITRAL Report of Working Group III, Oct–Nov 2018, para 67; Impartiality: International Adjudication) and required by general principles of international law (Mauritius v United Kingdom, 2011, paras 135, 138; General Principles of International Procedural Law). Adjudicators of international courts and tribunals are thus required to be independent and impartial by constitutive documents and relevant instruments (eg Art 2 ICJ Statute; Art 14 (1) Convention on the Settlement of Investment Disputes Between States and Nationals of Other States (‘ICSID Convention’)). In permanent courts a judge may not sit in a particular case if there is a special reason to doubt his/her independence (eg Art 24 ICJ Statute; Art 8 ITLOS Statute) (Savadogo, 2017, 114–40), while an arbitrator is disqualified when justifiable doubts are found as to his/her independence or impartiality (Art 12 UNCITRAL Arbitration Rules 2010) or in case of a manifest lack of independence or impartiality (Art 57 ICSID Convention) (Cristani, 2014, 159–64).

32  Since States may wish to block re-election of an adjudicator who voiced or voted against their interests (Polonskaya, 2020, 423 on the UK’s blocking of Guerrero’s reelection at the ICJ; Statement by the United States at the Meeting of the WTO Dispute Settlement Body, 2016, 1, on the US’s blocking of Chang’s reappointment at the WTO Appellate Body), those who wish to be re-elected may (be perceived to) be less vocal to avoid antagonizing States-voters (Malenovský, 2011, 190–95). One possible option to enhance the independence of judges at permanent courts and tribunals is to make their terms non-renewable (Art 2 (1) Institut de droit international, 2011). The term of ICC judges is non-renewable (Art 36 (9) (a) Rome Statute) precisely for this purpose (David, 2005, 394). The same applies to ECtHR judges, whose term was made non-renewable in 2010 (Council of Europe, 2004, para 50).

33  However it is often argued that a long non-renewable term undermines the legitimacy of a court or a tribunal as it may give adjudicators excessive freedom and lead them to go beyond their assigned task (Judicial Activism). For example, the US maintains that WTO Members have the responsibility to decide whether to reappoint an Appellate Body member by assessing whether he/she has been ‘independent’ (Statement by the United States at the WTO Dispute Settlement Body’s First ‘Dedicated Session’ on the Issue of Reappointments of Appellate Body Members, 2016, 5). Similarly, it is also pointed out that professional experience that signals a greater likelihood of independence or lower levels of political sensitivity work negatively in the election process of ICJ judges (Creamer and Godzimirska, 2017, 965). In this context, Dunoff and Pollack point out the ‘judicial trilemma’: the States that design international courts and tribunals confront an interlocking set of potential trade-offs in pursuit of three core values consisting in independence, accountability, and transparency (Dunoff and Pollack, 2017).

34  However it is in the field of investor-State arbitration that it is most frequently argued that the legitimacy of adjudicators (arbitrators) is undermined because of their lack of independence or impartiality. In investor-State arbitration arbitrators are often perceived as being less independent or impartial as they are considered to be motivated to ‘develop what are referred to as positions that would lead to repeat appointments’ (UNCITRAL WGIII, April 2018, paras 54–56). The common practice of double-hatting—the same person sits as arbitrator in one case and appears as counsel in another—has also raised concerns about arbitrators’ legitimacy; as arbitrators they are perceived to decide on an issue in one manner to benefit a party that they, as counsel, represent in another dispute (UNCITRAL WGIII, Oct—Nov 2018, para 72). In the face of mounting criticism, recent investment treaties have started to prohibit the practice of double-hatting at least to a certain extent (Art 3 (d) Code of conduct for investor-State dispute settlement under the Comprehensive and Progressive Agreement for Trans-Pacific Partnership) and to opt for a permanent investment court to break with the current party-appointment system (Arts 8.27, 8.28 Comprehensive Economic and Trade Agreement) (Ethical Standards for International Arbitrators).

35  In arbitration the legitimacy of the tribunal may also be called into question by the State party that considers the appointing authority lacks independence or impartiality. China’s criticism mentioned in the introduction of this entry is one of such rare examples.

36  A different kind of criticism from the perspective of impartiality is often addressed to the ICC. In 2009 when the ICC Pre-Trial Chamber issued an arrest warrant against Sudan’s President Al Bashir over the Darfur crisis, the Assembly of the African Union (‘AU’) decided that the AU Member States should not cooperate with the ICC for his arrest and surrender (Assembly of the AU, 2009, para 10). When the Pre-Trial Chamber issued a second arrest warrant against Al Bashir in the following year, the Assembly adopted a similar decision, expressing concern over the conduct of the ICC prosecutor, ‘who has been making egregiously unacceptable, rude and condescending statements on the case of President Omar Hassan El-Bashir of The Sudan and other situations in Africa’ (Assembly of the AU, 2010, para 9). A number of African leaders criticize the ICC for being ‘a biased instrument of post-colonial hegemony’ (Ssenyonjo, 2017, 222), guilty of selective justice by unfairly targeting Africa (Naldi and Magliveras, 2017, 115).

37  Procedural fairness, which includes, among others, equal treatment of parties and a reasonable distribution of procedural benefits and burdens, is generally considered to be an element influencing the legitimacy of international courts and tribunals (Grossman, 2009, 124; Shany, 2014, 142). The most striking precedent in this respect is the Croatia/Slovenia arbitration. During the proceedings it was revealed that the arbitrator appointed by Slovenia disclosed confidential information about the tribunal’s deliberation to one of the two agents acting for Slovenia. Following press reports, both the arbitrator and the agent resigned from their posts (Arbitration Between the Republic of Croatia and the Republic of Slovenia, 2016 (‘Croatia/Slovenia 2016’), para 6). Several days after their resignation the Prime Minister of Croatia stated: ‘The credibility and integrity of the arbitration process as a whole have been to such an extent compromised that, unfortunately, Croatia is not of the opinion that the arbitration process can continue in this or a similar form’ (Milanović, 2015, 1). Although Croatia took steps to terminate the arbitration agreement alleging Slovenia’s material breach, the recomposed tribunal decided to continue to function, considering that ‘the procedural balance between the Parties [was] secured … on the basis of all remedial action taken and … a further opportunity [given to each Party to express its views]’ (Croatia/Slovenia, 2016, para 194) and rendered its award in 2017 (Arbitration Between the Republic of Croatia and the Republic of Slovenia, 2017). Croatia, however, declared that it would not accept the results of this ‘obviously compromised’ arbitration process (Statement of the Government of the Republic of Croatia on the Arbitral Tribunal's award of 29 June 2017, 2017, para 4).

38  The legitimacy of international adjudicators is also measured on the basis of outcomes produced by international courts and tribunals. It involves an assessment of the compatibility of their decisions with applicable legal norms and substantive justice (Shany, 2018, 358–59; Effectiveness of International Adjudication).

39  International courts and tribunals are often criticized for being excessively conservative in applying rules that those who contest consider outdated. The 1966 judgment of the ICJ in the South West Africa cases was seen by many developing States to be illegitimate and risk damaging peoples’ confidence in the United Nations, of which the ICJ is the principal judicial organ (Fischer, 1966, 145–49; Bipoun-Woum, 1970, 196–97). It is generally understood that the 1966 judgment made developing States reluctant to bring their disputes to the ICJ for certain period of time following the judgment (Anand, 1976, 3–8) and inclined toward the creation of the ITLOS to depart from the ICJ, which was perceived as protecting the interests of industrialized Western States (Adede, 1975, 818).

40  To the contrary, international courts and tribunals often come under fire from those who consider that the rules they apply are too progressive to fall within the realm of positive law. An example of this is the AU’s decision not to cooperate with the ICC, which was motivated by African States’ understanding that the immunity of officials under customary international law shall be respected in the application of universal jurisdiction (Assembly of the AU, 2009, para 10; Official Records of the UNGA Sixth Committee, 2011, paras 12 (Kenya, on behalf of the Group of African States), 37 (Sudan), 38 (Ethiopia), 48 (DRC); 56 (Zambia); 68 (Senegal)).

41  There is another kind of contestation of the outcome-oriented legitimacy of international adjudicators. Following the 2012 judgment in Jurisdictional Immunities of the State, in which the ICJ found that Italy had violated its obligation to respect the immunity which Germany enjoyed by allowing civil claims to be brought against it based on violations of international humanitarian law committed by the German Reich during the Second World War (Jurisdictional Immunities of the State, Germany v Italy (Greece intervening), 2012, 155), the legislative and executive branches of Italy took the necessary measures to implement the judgment. However, the Italian Constitutional Court found that Italian laws that obliged Italy to implement the said judgment were unconstitutional. To justify its conclusion the Constitutional Court clearly distinguished between the international legal order and the Italian domestic legal order; while recognizing that the ICJ’s judgment was particularly qualified and did not allow further examination by national courts at the international law level, it held that its implementation in the Italian domestic legal order was unconstitutional. However, the Constitutional Court went on to say that the relevant international law rules were changing and that its judgment might contribute to a ‘desirable and desired’ evolution of international law (Corte Costituzionale, 2014, paras 3.1, 3.3, 3.5). Thus, the court does not formally question the ICJ’s judgment in light of positive law but attempts to render it irrelevant pursuant to the standard of justice that it finds appropriate.

42  As often pointed out arguments on legitimacy are fuzzy and indeterminate in comparison to strictly legal arguments, and ‘legitimacy-speak’ allows lawyers to break free from disciplinary constraints to assert their own moral intuitions (Crawford, 2004, 271). It is true that arguments on legitimacy cannot replace legal arguments on lex lata. However normative legitimacy can help identify where international courts and tribunals are lacking and what can be done to strengthen them (Grossman, 2013, 64). A contestation of the normative legitimacy of an international court or tribunal is intended to have dynamic effects that would prompt a modification or evolution of the substantive legal norms applied by the court or tribunal (eg the AU’s reaction to ICC or the 2014 judgment of the Italian Constitutional Court) as well as systemic changes in the institutional aspects of the court or tribunal (US’ attitude towards the WTO Appellate Body or criticisms addressed to investor-State arbitration). Such criticism de lege ferenda cannot be understood and addressed as long as one stays in the strictly legal field (Madsen and others, 2018, 200–1). If a contestation of the normative legitimacy of an international court or tribunal by a State or a group of States attracts wide support, the court or tribunal may be reorganized or led to modify its line of jurisprudence, or States may decide not to refer disputes to it or simply withdraw from it (Follesdal, 2019, 235–36).

Shotaro Hamamoto