1 Reservations to the Convention on Genocide, Advisory Opinion of 28 May 1951, [1951] ICJ Rep. 15, at 23 (hereafter ‘Reservations’).

2 The term ‘multilateral’ does not itself describe obligations that are owed in the collective interest. Certain obligations are only multilateral to the extent that ‘they bind more than two states’; they are bilateral obligations in multilateral form. C. Dominicé, ‘The International Responsibility of States for Breach of Multilateral Obligations’, (1999) 10 EJIL 353, at 354. See also J. Crawford, Chance, Order, Change (2014), para. 307; C. J. Tams, Enforcing Obligations Erga Omnes in International Law (2005), 45.

3 Multilateral treaties that expressly confer a right of standing upon states parties are not therefore addressed. For an overview, see Tams, ibid., at 71–6; E. Brown Weiss, ‘Invoking State Responsibility in the Twenty-First Century’, (2002) 96 AJIL 798, at 805–6; J. Crawford, State Responsibility: The General Part (2013), 390.

4 Barcelona Traction, Light and Power Company, Limited (Belgium v. Spain), Judgment of 5 February 1970, [1970] ICJ Rep. 3, at 32, para. 33 (hereafter ‘Barcelona Traction’). See also Art. 1(a)–(b), Obligations Erga Omnes in International Law, Institut de Droit Internationale (2005). The term is not used to describe obligations under a multilateral treaty which ‘expressly provides for standing in the public interest’. C. J. Tams and A. Tzanakopoulos, ‘Barcelona Traction at 40: The ICJ as an Agent of Legal Development’, (2010) 23 LJIL 781, at 794.

5 P. Weil, ‘Towards Relative Normativity in International Law?’, (1983) 77 AJIL 413, at 432. It is sometimes suggested that obligations erga omnes are not owed to states individually but to the international community as a whole. The position must be rejected, particularly in a discussion of standing, since ‘it is nonsensical if the “party” to which the obligation is owed is a collective one without the capacity to act’. Crawford, supra note 2, para. 340. See also Weil, ibid.; Tams, supra note 2, at 174–5.

6 Weil, ibid., at 431; B. Simma, ‘From Bilateralism to Community Interest in International Law’, (1994) 250 Collected Courses of the Hague Academy of International Law 224, at 295; Crawford, supra note 2, para. 310; Tams, supra note 2, at 29.

7 Crawford, supra note 2, para. 339.

8 ILC Articles on the Responsibility of States for Internationally Wrongful Acts, 2001 YILC, vol. II (Part Two), at 117 (hereafter ‘Commentary’). The focus of the article being the adjudication of disputes at the ICJ, other means of dispute settlement are not addressed. For an overview see S. Scott, ‘Litigation versus Dispute Resolution through Political Processes’, in N. Klein (ed.), Litigating International Law Disputes: Weighing the Options (2014), 24. The question of the interaction between countermeasures and adjudication also arises. As stated in Art. 52(3)(a) of the ARSIWA, countermeasures are excluded while a dispute is pending adjudication. See also J. D. Bederman, ‘Counterintuiting Countermeasures’, (2002) 96 AJIL 817, at 826; J. Crawford, ‘The ILC’s Articles on Responsibility of States for Internationally Wrongful Acts: A Retrospect’, (2002) 96 AJIL 874, at 883–4.

9 Commentary, ibid. Put differently, ‘[f]or a state to enjoy a right implies its possession of legal standing to claim performance of the corresponding obligation’. Weil, supra note 5, at 431.

10 Tams, supra note 2, at 26. On standing generally, see G. Gaja, ‘Standing: International Court of Justice (ICJ)’, in H. Ruiz Fabri (ed.), Max Planck Encyclopedia of International Procedural Law (2018).

11 D. D. Caron, ‘The ILC Articles on State Responsibility: The Paradoxical Relationship between Form and Authority’, (2002) 96 AJIL 857, at 866. See also Crawford, supra note 3, at 390.

12 M. Kawano, ‘Standing of a State in the Contentious Proceedings of the International Court of Justice’, (2012) 55 Japanese Yearbook of International Law 208, at 235.

13 On this subject see F. Berman, ‘The International Court of Justice as an “Agent” of Legal Development?’, in C. J. Tams and J. Sloan (eds.), The Development of International Law by the International Court of Justice (2013), 7; A. Pellet, ‘Shaping the Future of International Law: The Role of the World Court in Law-Making’, in M. H. Arsanjani et al. (eds.), Looking to the Future: Essays on International Law in Honour of W. Michael Reisman (2011), 1065.

14 See, e.g., G. Gaja, ‘Interpreting Articles Adopted by the International Law Commission’, (2015) 85 BYIL 10; Crawford, supra note 3, Ch. 11. The General Assembly’s adoption of the Articles by resolution stopped short, on the recommendation of the ILC, of convening ‘an international conference of plenipotentiaries to examine the draft articles … with a view to concluding a convention on the topic’. Official Records of the General Assembly, Fifty-Sixth Session, Supplement No. 10 (A/56/10), paras. 72–3. For some, the level of abstraction at which the Articles are pitched makes them influential, even if ‘as a statement of principle … [rather] than as a legally binding treaty’. Bederman, supra note 8, at 828–9. As Caron warned, however, the Articles are not themselves a source of law, and their contribution – notwithstanding their articulation in statutory form – must not be overstated. Caron, supra note 11, at 867. See also F. Paddeu, ‘To Convene or Not to Convene? The Future Status of the Articles on State Responsibility: Recent Developments’, (2018) 21 Max Planck Yearbook of United Nations Law 83.

15 Art. 33(1), Articles on the Responsibility of States for Internationally Wrongful Acts 2001 (hereafter ‘ARSIWA’). As one commentator remarks, this taxonomy was ‘innovative, if perhaps controversial’. Brown Weiss, supra note 3, at 801.

16 Commentary, supra note 8, at 118; Dominicé, supra note 2, at 357.

17 The inclusion of these provisions followed a debate about whether the breach of all obligations should trigger the application of the same regime of responsibility. See Fifth Report on State Responsibility, by Mr. Roberto Ago, Special Rapporteur, 1976, YILC vol. II (Part One), at 24, 26, paras. 72, 80.

18 The provision is modelled on Art. 60 of the Vienna Convention on the Law of Treaties (VCLT). See Commentary, supra note 8.

19 See Art. 42(b)(i), ARSIWA, reflecting Art. 60(2)(b), VCLT. The state ‘must be affected by the breach in a way which distinguishes it from the generality of other States to which the obligation is owed’. Commentary, ibid., at 119.

20 See Art. 42(b)(ii), ARSIWA, reflecting Art. 60(2)(c), VCLT. This clause addresses the category of integral or inter-dependent obligations, the breach of which ‘affect[s] per se every other State to which the obligation is owed’ such that ‘they must all be considered as individually entitled to react to [the] breach’. Commentary, ibid., at 119. In other words, ‘each party’s performance is effectively conditioned upon and requires the performance of each of the others’. ibid.

21 See Ch. II, Part 3, ARSIWA.

22 The Articles do not use the term ‘legal interest’ to describe the entitlement to invoke responsibility under Art. 48, since this would have blurred the distinction between Art. 42 and Art. 48. Commentary, supra note 8, at 126.

23 Ibid.

24 Ibid., at 127.

25 See also ibid.

26 Ibid.

27 Crawford, supra note 3, at 551.

28 Commentary, supra note 8, at 127.

29 International obligations being increasingly ‘unilateral or vertical’, the selection of remedies in Art. 48(2) may be explained by the fact that ‘[b]reach of these duties is unlikely to injure another state directly or give rise to a classic claim for reparations’. The emphasis on cessation is justified by states’ interest in continued compliance with these obligations. D. Shelton, ‘Righting Wrongs: Reparations in the Articles on State Responsibility’, (2002) 96 AJIL 833, at 834.

30 The Commission noted that ‘[p]ractice on this subject is limited and rather embryonic’. Commentary, supra note 8, at 137. On the objection of some states, the provision was therefore ‘reduced … from a substantive article to a savings clause’. Crawford, supra note 8, at 875.

31 Bederman, supra note 8, at 828. To whatever extent subsequent state practice supports the use of countermeasures for the enforcement of obligations erga omnes, it may bear on the permissibility of recourse to the ICJ. See generally, M. Dawidowicz, ‘Third-Party Countermeasures: A Progressive Development of International Law?’, (2016) 29 QIL Zoom-In 3; C. Hillgruber, ‘The Right of Third States to Take Countermeasures’, in C. Tomuschat and J.-M. Thouvenin (eds.), The Fundamental Rules of the International Legal Order (2006), 265, at 283–7.

32 Commentary, supra note 8, at fn 724.

33 SS Wimbledon, PCIJ Rep. Series A No 1, 15, at 20.

34 Ibid.

35 South West Africa Cases (Ethiopia v. South Africa; Liberia v. South Africa), Judgment of 18 July 1966, [1966] ICJ Rep. 6, at 18, para. 4 (hereafter ‘South West Africa’).

36 South West Africa Cases (Ethiopia v. South Africa; Liberia v. South Africa), Preliminary Objections, Judgment of 21 December 1962, [1962] ICJ Rep. 319, at 343.

37 It was perhaps relevant that the Covenant of the League of Nations, unlike the Treaty of Versailles, did not establish an objective legal regime. C. Fernández de Casadevante Romani, ‘Objective Regime’, (2010) Max Planck Encyclopedia of Public International Law, paras. 6–7.

38 For the Court, ‘[j]urisdictional clauses do not determine whether parties have substantive rights, but only whether, if they have them, they can vindicate them by recourse to a tribunal’. South West Africa, supra note 35, at 39, para. 65. The same issue had been raised by the parties in Case Concerning the Northern Cameroons (Cameroon v. United Kingdom), wherein the jurisdiction clause in Art. 19 of the trusteeship agreement for the Cameroons had been in question. The Court did not, however, address the issue. Case Concerning the Northern Cameroons (Cameroon v. United Kingdom), Judgment of 2 December 1963, [1963] ICJ Rep. 15, at 35.

39 South West Africa, supra note 35, at 25, para. 24. For alternative explanations see V. Kattan, ‘“There was an elephant in the courtroom”: Reflections on the Role of Judge Sir Percy Spender (1897–1985) in the South West Africa Cases (1960–1966) after Half a Century’, (2018) 31 LJIL 147; I. Venzke, ‘Public Interests in the International Court of Justice – A Comparison between Nuclear Arms Race (2016) and South West Africa (1966)’, (2017) 111 AJIL Unbound 68, at 69–70.

40 South West Africa, ibid., at 32, para. 44. That is, ‘to generate legal rights and obligations, [the interest] must be given juridical expression and be clothed in legal form’. Ibid., at 34, para. 51.

41 Ibid., at 47, para. 88.

42 Commentary, supra note 8, at 127. The Court’s reference at paragraph 34 to ‘instruments of a … quasi-universal character’ suggest that its statements also address the content of Art. 48(1)(a), that is obligations erga omnes partes.

43 Barcelona Traction, supra note 4, at 32, paras. 33–4.

44 But see ibid., at 47, para. 91. Whether the Court’s subsequent statement at para. 91 serves to exclude the broad right of standing expressed here is subject to debate. Interpretations which retain the effectiveness of the dictum at paras. 33 and 34 are preferred. Simma, supra note 6, at 296; but see Dominicé, supra note 2, at 362. For a detailed discussion see J. Crawford, ‘Multilateral Rights and Obligations in International Law’, (2006) 319 Collected Courses of the Hague Academy of International Law 329, at 424–5; Tams, supra note 2, at 176–9.

45 Tams, ibid., at 123.

46 Tams and Tzanakopoulos, supra note 4, at 796–7.

47 The value of the Court’s dictum is subject to debate. It is often suggested that its statements were an attempt to correct its heavily criticised approach in South West Africa, and an exercise in judicial activism. F. Zarbayev, ‘Judicial Activism in International Law – A Conceptual Framework for Analysis’, (2012) 3 JIDS 247, at 276–7. It may also be that the Court was setting the stage for subsequent developments. N. Ridi, ‘“Mirages of an Intellectual Dreamland”? Ratio, Obiter and the Textualization of International Precedent’, (2019) 10 JIDS 361, at 381–2.

48 Nuclear Tests (Australia v. France), Judgment of 20 December 1974, [1974] ICJ Rep. 253, at 437 (Judge Barwick, Dissenting Opinion). Based on his reading of the joint dissenting opinion of Judges Onyeama, Dillard, Jiménez de Aréchaga, and Waldock, Tams goes further in concluding that ‘the majority of judges expressing a view was prepared to take the Barcelona Traction dictum at face value’. Tams, supra note 2, at 180–2.

49 Ibid., at 387 (Judge de Castro, Dissenting Opinion) (hereafter ‘de Castro Dissent’).

50 Application of the Convention on the Prevention and Punishment of the Crimes of Genocide, Judgment of 11 July 1996, [1996] ICJ Rep. 595 (hereafter ‘Bosnian Genocide’), at 626, para. 4 (Judge Oda, Declaration) (hereafter ‘Oda Declaration’).

51 Art. IX, Convention on the Prevention and Punishment of the Crime of Genocide.

52 Oda Declaration, supra note 50, at 626, para. 3.

53 Ibid., at 626, paras. 4, 6.

54 East Timor (Portugal v. Australia), Judgment of 30 June 1995, [1995] ICJ Rep. 90, at 99, para. 20 (hereafter ‘East Timor’).

55 Ibid., at 102, para. 29.

56 Ibid., at 105, para. 35.

57 Ibid., at 102, para. 29.

58 East Timor, supra note 54, at 172 (Judge Weeramantry, Dissenting Opinion) (hereafter ‘Weeramantry Dissent’). See also Gabčíkovo-Nagymaros Project (Hungary v. Slovakia), Judgment of 25 September 1997, [1997] ICJ Rep. 88, at 117–19 (Judge Weeramantry, Separate Opinion) (hereafter ‘Weeramantry Separate Opinion’).

59 J. A. Frowein, ‘Reactions by Not Directly Affected States to Breaches of Public International Law’, (1994) 248 Collected Courses of the Hague Academy of International Law 350, at 429; Simma, supra note 6, at 297. But see Tams, supra note 2, at 184.

60 Judgment of 20 July 2012, [2012] ICJ Rep. 422 (hereafter ‘Obligation to Extradite’). For Crawford, the decision is ‘firmly in line with’ Art. 48, ARSIWA. Crawford, supra note 3, at 370. See also B. Simma, ‘The ICJ and Human Rights’, in C. J. Tams and J. Sloan (eds.), The Development of International Law by the International Court of Justice (2013), 301, at 314.

61 Obligation to Extradite, ibid., at 444, para. 53.

62 Questions relating to the Obligation to Prosecute or Extradite (Belgium v. Senegal), Memorial of Belgium of 1 July 2010, 79–80, paras. 5.14–5.18.

63 Obligation to Extradite, supra note 60, at 449, para. 68. Judge ad hoc Sur questioned whether all the obligations arising under the Convention derive from the prohibition of torture, thereby rendering them obligations erga omnes partes. Ibid., at 613–15, paras. 27–30, 34 (Judge ad hoc Sur, Dissenting Opinion) (hereafter ‘Sur Dissent’). See also ibid., at 575, para. 17 (Judge Xue, Dissenting Opinion) (hereafter ‘Xue Dissent’).

64 Ibid., at 450, para. 69.

65 Ibid., para. 70.

66 Xue Dissent, supra note 63, at 574, para. 14.

67 Sur Dissent, supra note 63, at 618, para. 44.

68 Xue Dissent, supra note 63, at 574–5, paras. 15–16. Judge ad hoc Sur also questioned the Court’s implicit reliance on the ARISWA. Sur Dissent, ibid., at 614–15, paras. 30–31.

69 Xue Dissent, ibid., at 575, para. 17.

70 Obligation to Extradite, supra note 60, at 450, para. 69.

71 Xue Dissent, supra note 63, at 576, para. 19.

72 Ibid., at 577, paras. 22–3; Sur Dissent, supra note 63, at 616–17, para. 39.

73 Sur Dissent, ibid., at 616, para. 36.

74 Obligation to Extradite, supra note 60, at 444–5, para. 54. As noted by Judge ad hoc Sur, limited explanation was offered in support of the majority’s view. Sur Dissent, ibid., at 610, para. 17.

75 Judgment of 31 March 2014, [2014] ICJ Rep. 226 (hereafter ‘Whaling’).

76 Whaling in the Antarctic (Australia v. Japan; New Zealand Intervening), Australia’s Application Instituting Proceedings, 31 May 2010, para. 2. During oral proceedings, Australia clarified that it was seeking ‘to uphold its collective interest, an interest it shares with all other parties’. Verbatim Record CR 2013/18, 9 July 2013, 28, para. 19.

77 See Whaling, supra note 75, at 242–3, paras. 32–3.

78 See ibid., at 251–2, paras. 56–8.

79 P. Urs, ‘Guest Post: Are States Injured by Whaling in the Antarctic?’, Opinio Juris, 14 August 2014, available at opiniojuris.org/2014/08/14/guest-post-states-injured-whaling-antarctic/; M. Fitzmaurice, Whaling and International Law (2015), 109–10. This is also how Japan’s Foreign Ministry understood the decision. Cf. Fitzmaurice, ibid., at 114.

80 For an explanation of the dynamics of the case see C. J. Tams, ‘Roads Not Taken, Opportunities Missed: Procedural and Jurisdictional Questions Sidestepped in the Whaling Judgment’, in M. Fitzmaurice and D. Tamada (eds.), Whaling in the Antarctic: The Significance and the Implications of the ICJ Judgment (2016), 193, at 206–9. Australia’s approach was ‘unusual’ since ‘claimant States had usually opted for a different, “dualistic”, approach that emphasised the right to vindicate general interests but also stressed the claimant State’s special position’. Tams, ibid., at 204. See also T. Stephens, ‘Law of the Sea Symposium: A Comment on Natalie Klein’s Post’, Opinio Juris, 27 May 2013, available at opiniojuris.org/2013/05/27/law-of-the-sea-symposium/; Crawford, supra note 3, at 373.

81 Obligations concerning Negotiations relating to Cessation of the Nuclear Arms Race and to Nuclear Disarmament (Marshall Islands v. United Kingdom), Judgment of 5 October 2016, [2016] ICJ Rep. 833 (hereafter ‘Marshall Islands’); Obligations concerning Negotiations relating to Cessation of the Nuclear Arms Race and to Nuclear Disarmament (Marshall Islands v. India), Judgment of 5 October 2016, [2016] ICJ Rep. 255; Obligations concerning Negotiations relating to Cessation of the Nuclear Arms Race and to Nuclear Disarmament (Marshall Islands v. Pakistan), Judgment of 5 October 2016, [2016] ICJ Rep. 552.

82 Marshall Islands, ibid., at 854, paras. 20, 44–58.

83 For the view that the Court might have been better off dismissing the cases for inadmissibility see V.-J. Proulx, ‘The Marshall Islands Judgment and Multilateral Disputes at the World Court: Whither Access to International Justice?’, (2017) 111 AJIL Unbound 96.

84 Obligations concerning Negotiations relating to Cessation of the Nuclear Arms Race and to Nuclear Disarmament (Marshall Islands v. United Kingdom), Judgment of 5 October 2016, [2016] ICJ Rep. 1093, at 1102, para. 21 (Judge Crawford, Dissenting Opinion). See also F. Paddeu, ‘Multilateral Disputes in Bilateral Settings: International Practice Lags Behind Theory’, (2017) 76(1) Cambridge Law Journal 1, at 2–3.

85 This did not, however, make all nuclear weapons states indispensable third parties. Supra note 81, at 898, para. 38 (Judge Tomka, Separate Opinion).

86 Application of the Convention on the Prevention and Punishment of the Crime of Genocide (The Gambia v. Myanmar), The Gambia’s Application Instituting Proceedings and Request for Provisional Measures, 11 November 2019, para. 15 (not yet published).

87 Ibid.

88 See, e.g., Bosnian Genocide, supra note 50, at 615, para. 31.

89 Barcelona Traction, supra note 4, at 32, para. 34.

90 Obligation to Extradite, supra note 60, at 449, para. 68.

91 Reservations, supra note 1, at 23. See also ibid., at 51 (Judge Álvarez, Dissenting Opinion) (hereafter ‘Álvarez Dissent’).

92 Application of the Convention on the Prevention and Punishment of Genocide (The Gambia v. Myanmar), Order for Provisional Measures of 23 January 2020, para. 41 (not yet published) (hereafter ‘Rohingya Genocide’).

93 Ibid., para. 35.

94 Verbatim Record CR 2019/19, 11 December 2019, 53, para. 56 (hereafter ‘Verbatim Record I’).

95 Ibid., at 53, paras. 55–6.

96 Application of the Convention on the Prevention and Punishment of Genocide (The Gambia v. Myanmar), Order for Provisional Measures of 23 January 2020, para. 6 (Judge Xue, Separate Opinion) (not yet published) (hereafter ‘Xue Separate Opinion’).

97 Ibid., para. 7. See also M. Ruffert, ‘Special Jurisdiction of the ICJ in the Case of Infringement of Fundamental Rules of the International Legal Order?’, in C. Tomuschat and J.-M. Thouvenin (eds.), The Fundamental Rules of the International Legal Order (2006), 295, at 307.

98 Crawford, supra note 3, at 378.

99 See Paddeu, supra note 84.

100 Simma, supra note 6, at 295.

101 Tams, supra note 2, at 102. This is indeed the better view. If obligations erga omnes did not give rise to a right of standing, the concept would be ‘of rhetorical value only’. Tams, ibid., at 158. In support see C. Tomuschat, ‘Obligations Arising for States Without or Against their Will’, (1993) 241 Collected Courses of the Hague Academy of International Law 203, at 365; Frowein, supra note 59, at 427; Crawford, supra note 44, at 425. For a detailed discussion see Tams, ibid., at 162–80.

102 De Castro Dissent, supra note 49, at 387. See also Brown Weiss, supra note 3, at 801.

103 See Kawano, supra note 12, at 230; M. Andenas and T. Weatherall, ‘International Court of Justice: Questions Relating to the Obligation to Extradite or Prosecute (Belgium v Senegal) Judgment of 20 July 2012’, (2013) 62 ICLQ 753, at 765–6.

104 See supra note 79.

105 Tams, supra note 80, at 210.

106 Crawford, supra note 44, at 423.

107 But see Andenas and Weatherall, supra note 103, at 764.

108 See also J. Heieck, ‘Rohingya Symposium: Judicial Intervention and the Duty to Prevent Genocide in the Rohingya Genocide Case – The Role of Obligatio Erga Omnes and Nouvelle Protection Diplomatique’, Opinio Juris, 25 August 2020, available at opiniojuris.org/2020/08/25/rohingya-symposium-judicial-intervention-and-the-duty-to-prevent-genocide-in-the-rohingya-genocide-case-the-role-of-obligatio-erga-omnes-and-nouvelle-protection-diplomatique/.

109 Indeed, it is more difficult to establish the content of an obligation erga omnes under customary international law. Kawano, supra note 12, at 215–16.

110 See, e.g., Art. 3, Obligations Erga Omnes under International Law, Resolution of the Institut de Droit Internationale (2005); Tams, supra note 2, at 161–2; G. Gaja, ‘The Protection of General Interests in the International Community’, (2011) 364 Collected Courses of the Hague Academy of International Law 15, at 111–12; Kawano, supra note 12, at 219–20; S. Villalpando, ‘The Legal Dimension of the International Community: How Community Interests are Protected in International Law’, (2010) 21 EJIL 387, at 414–15.

111 Tams, supra note 2, at 159–60.

112 Frowein, supra note 59, at 427.

113 Weeramantry Separate Opinion, supra note 58, at 118. See also Weeramantry Dissent, supra note 58, at 172–3.

114 East Timor, supra note 54, at 104–5, para. 34.

115 Ibid. See also Ruffert, supra note 97, at 303–4.

116 Simma, supra note 6, at 297.

117 Weeramantry Dissent, supra note 58, at 173.

118 See Certain Phosphate Lands in Nauru (Nauru v. Australia), Preliminary Objections, Judgment of 26 June 1992, [1992] ICJ Rep. 240, at 261, para. 55. See also Gaja, supra note 110, at 118. Neither does the indispensable third-party rule require the participation in the proceedings of all states to which the obligation is owed. Ibid., at 117–18.

119 Case Concerning Armed Activities on the Territory of the Congo (New Application: 2002) (Democratic Republic of the Congo v. Rwanda), Provisional Measures, Order of 10 July 2002, [2002] ICJ Rep. 219, at 245–6, paras. 71–2.

120 The permissibility of a reservation, if unspecified, depends on the reservation’s compatibility with the object and purpose of the treaty. Reservations, supra note 1, at 24. As Simma explains, community interest in multilateral treaties ‘manifests itself at two levels’. First, through ‘adherence by as large a number of States as possible’, notwithstanding that a state ‘has relativized its consent to the substance of the treaty by way of reservations’, and secondly, to maintain ‘the integrity of at least the essence of the treaty obligations by stating the precondition of the compatibility of the reservations made with the object and purpose of the treaty’. Simma, supra note 6, at 340–2.

121 Xue Separate Opinion, supra note 96, para. 6.

122 Sur Dissent, supra note 63, at 616–17, para. 39.

123 Xue Separate Opinion, supra note 96, para. 6.

124 Álvarez Dissent, supra note 91, at 52–3. See also Simma, supra note 6, at 342–4; Crawford, supra note 2, para. 324.

125 Simma, ibid., at 342.

126 The answer depends on whether a reservation to a compromissory clause constitutes a minor and therefore permissible reservation. Reservations, supra note 1, at 24.

127 Myanmar took the view that all its neighbouring states would be specially affected. It is unclear why this might be the case. See Verbatim Record I, supra note 94, at 53, para. 56; Verbatim Record, CR 2019/21, 12 December 2019, 14–15, paras. 15–17 (hereafter ‘Verbatim Record II’).

128 Verbatim Record I, ibid.

129 Weeramantry Dissent, supra note 58, at 172. See also Simma, supra note 6, at 330–1.

130 Verbatim Record II, supra note 127, at 15, para. 16 (Myanmar arguing that ‘the right of non-injured States to invoke … responsibility is subsidiary’ to the right of an injured state to do so).

131 Shelton, supra note 29, at 854.

132 S. R. Singh, ‘Standing on “Shared Values”: The ICJ’s Myanmar Decision and Its Implications for Atrocity Prevention’, Opinio Juris, 29 January 2020, available at opiniojuris.org/2020/01/29/standing-on-shared-values-the-icjs-myanmar-decision-and-its-implications-for-atrocity-prevention/.

133 Shelton, supra note 29, at 839–40.

134 The ILC anticipated that a state other than an injured state seeking reparation for a breach ‘may be called on to establish that it is acting in the interest of the injured party’, which, if a state, will be able to represent its own interests. Commentary, supra note 8, at 127.

135 See Arts. 59–60, ICJ Statute.

136 Discussion of the remedies that may be awarded to a state other than an injured state is limited. To date, the Court has not purported to limit itself to the remedies specified in Art. 48(2) ARSIWA, imposing, for example, a reporting requirement on Myanmar as a provisional measure in Rohingya Genocide. For the view that the Court also went beyond the remedies sought by Australia in the Whaling decision see Tams, supra note 80, at 209.

137 Commentary, supra note 8, at 126.

138 See Weeramantry Dissent, supra note 58, at 172–3. For an overview of the ICJ’s approach to res judicata see N. Ridi, ‘Precarious Finality? Reflections on Res Judicata and the Question of the Delimitation of the Continental Shelf Case’, (2018) 31 LJIL 383.

139 See Art. 45, ARSIWA.

140 The Commission neither affirmed nor denied the continued availability of Article 48 where an injured state has lost its right to invoke responsibility. Commentary, supra note 8, at 122. Elsewhere, Crawford considers that ‘where there are continuing obligations to a wider group of states, settlement between the two states directly involved in the claim may be insufficient to resolve matters fully’. Crawford, supra note 3, at 563. While Crawford argues that ‘it does not necessarily follow’ from the waiver of the injured state that ‘all the rights to claim of all other states under article 48’ are extinguished, Tams contends that the waiver of a claim by an injured state ‘would also extinguish all claims that “other interested States” have under article 48’. Cf. Crawford, supra note 3, at 564. If, as appears to be the approach taken in Rohingya Genocide, obligations erga omnes operate erga singulum, the former approach is preferred.

141 Obligation to Extradite, supra note 60, at 450, para. 69. See also Tams and Tzanakopoulos, supra note 4, at 794; Brown Weiss, supra note 3, at 805.

142 See www.foreign.gov.mv/index.php/en/mediacentre/news/5483-the-republic-of-maldives-to-file-declaration-of-intervention-in-support-of-the-rohingya-people,-at-the-international-court-of-justice and www.government.nl/documents/diplomatic-statements/2020/09/02/joint-statement-of-canada-and-the-kingdom-of-the-netherlands-regarding-intention-to-intervene-in-the-gambia-v.-myanmar-case-at-the-international-court-of-justice.

143 There is no comparable right to intervene in respect of general international law. G. Gaja, ‘A New Way for Submitting Observations on the Construction of Multilateral Treaties to the International Court of Justice’, in U. Fastenrath et. al. (eds.), From Bilateralism to Community Interest: Essays in Honour of Bruno Simma (2011), 665, at 672.

144 Kawano, supra note 12, at 236.

145 Gaja, supra note 110, at 119. Cf. B. McGarry, ‘Third-State Intervention in the Rohingya Genocide Case: How, When, and Why? [Part I]’, Opinio Juris, 11 September 2020, available at opiniojuris.org/2020/09/11/third-state-intervention-in-the-rohingya-genocide-case-how-when-and-why-part-i/.

146 McGarry, ibid.

147 See Gaja, supra note 110, at 120–2. There is an interesting comparison to be made between the intervention in contentious cases of potentially all states to which the obligation erga omnes is owed and the Court’s advisory proceedings in which collective interests are also addressed and in which all states are entitled to participate.

148 Crawford, supra note 3, at 553.

149 Verbatim Record I, supra note 94, at 54, para. 57; Weil, supra note 5, at 433; Brown Weiss, supra note 3, at 805.

150 Proulx, supra note 83, at 101.

151 Crawford, supra note 2, para. 341.

152 Tams, supra note 2, at 24; Frowein, supra note 59, at 427. For the view that states are anyway unlikely to resort to countermeasures for the enforcement of obligations erga omnes see Tomuschat, supra note 101, at 367.

153 Singh, supra note 132.

154 See supra note 3.

155 Tams and Tzanakopoulos, supra note 4, at 792.

156 Scott, supra note 8, at 29. See also M. A. Becker, ‘The Situation of the Rohingya: Is There a Role for the International Court of Justice?’, EJIL: Talk!, 14 November 2018, available at www.ejiltalk.org/the-situation-of-the-rohingya-is-there-a-role-for-the-international-court-of-justice/.

157 P. Picone, ‘The Distinction between Jus Cogens and Obligations Erga Omnes’, in E. Cannizzaro (ed.), The Law of Treaties Beyond the Vienna Convention (2011), 411, at 423–4.

158 Brown Weiss, supra note 3, at 805. See also Tomuschat, supra note 101, at 367; Crawford, supra note 2, para. 341.

159 Paddeu, supra note 84, at 4.

160 Villalpando, supra note 110, at 413–14.