1 1 Guggenheim, P., Traité de droit international public 1 (2d ed. 1967): “le droit international public est l’ensemble des normes juridiques qui règlent les relations internationales.” Google Scholar

2 1 Rousseau, C., Droit international public 25–26 (1971)Google Scholar.

3 See Baxter, , International Law in “Her Infinite Variety,” 29 Int’l & Comp. L.Q. 549 et seq. (1980)CrossRefGoogle Scholar.

4 14 UST 1313, TIAS No. 5433, 480 UNTS 43.

5 Weil, , Le Droit international économique: mythe ou réalite?, in Aspects du droit international économique 1 (1972)Google Scholar.

6 Interpretation of the Agreement of 25 March 1951 between the WHO and Egypt, 1980 ICJ Rep. 73, 95 (Advisory Opinion of Dec. 20).

7 The term “soft law” is not used solely to express the vague and therefore, in practice, uncompelling character of a legal norm but is also used at times to convey the sublegal value of some non-normative acts, such as certain resolutions of international organizations, the Helsinki Final Act, and the Stockholm Declaration on the Environment (in addition to Baxter, note 3 supra, see the 1973 Hague Academy symposium on The Protection of the Environment and International Law (1975), esp. the contributions of Goldie, at 513 and 530, and Castañeda, at 534 et seq.; Dupuy, R.-J., Droit déclaratoire et droit programmatoire: de la coutume sauvage a la soft law, in L’Elaboration du droit international public 132 (1975)Google Scholar, translated in Declarations on principles: a quest for universal peace 237 (Akkerman, R.J., van Krieken, P.J., & Pannenborg, C. O. eds. 1977)Google Scholar). It would seem better to reserve the term “soft law” for rules that are imprecise and not really compelling, since sublegal obligations are neither “soft law” nor “hard law”: they are simply not law at all. Two basically different categories are involved here; for while there are, on the one hand, legal norms that are not in practice compelling, because too vague, there are also, on the other hand, provisions that are precise, yet remain at the pre- or subnormative stage. To discuss both of these categories in terms of “soft law” or “hard law” is to foster confusion.

8 For some recent studies of this problem, see, inter alia, Baxter, note 3 supra; Schachter, , The Twilight Existence of Non-Binding Agreements, 71 AJIL 296 (1977)CrossRefGoogle Scholar; and Bothe, , Legal and Non-Legal Norms: A Meaningful Distinction in International Relations?, 9 Neth. Y.B. Int’l L. 65 et seq. (1980)CrossRefGoogle Scholar. The question of “the distinction between international texts with a legal bearing and international texts without legal bearing (with the exception of texts emanating from international organizations)” is at present being studied by the Institute of International Law (rapporteur, M. Virally).

9 Judge Lauterpacht in South West Africa: Voting Procedure, 1955 ICJ Rep. 67, 115 (Advisory Opinion of June 7) (sep. op. Lauterpacht, J.).

10 These expressions (also to be found, with variants, in the writings of several contemporaries) are borrowed from Castaneda, J., Legal Effects of United Nations Resolutions 176 (1969)Google Scholar; cf. his La Valeur juridique des resolutions des Nations Unies, 129 Recueil des Cours 205, 320 (1970 I).

11 Cf. award in Texaco / Calasiatk v. Libya: UN resolutions “have varying legal value”; “while it is now possible to recognize that resolutions of the United Nations have a certain legal value, this legal value differs considerably.” 17 ILM 28–29, paras. 83 and 86 (1978) (emphasis added).

12 See supra note 7.

13 R.-J. Dupuy, supra note 7, at 146–47. See also Quoc Dinh, Nguyen, Daillier, P, & Pellet, A., Droit international public 338 (2d ed. 1980)Google Scholar; Pellet, A., Le Droit du développement 63 (1978)Google Scholar. Judge Lauterpacht proposed a different analysis: states are under an obligation to examine the resolutions in good faith and, if they decide to ignore them, to give the reasons for their decision. 1955 ICJ Rep. at 119.

14 Virally, , A propos de la lex ferenda, in Mélanges Reuter 519 (1981)Google Scholar.

15 Arangio-Ruiz, , The Normative Role of the General Assembly of the United Nations and the Declaration of Principles of Friendly Relations, 137 Recueil des Cours 419, 431 (1972 II)Google Scholar. See also Schwebel, , The Effect of Resolutions of the U.N. General Assembly on Customary International Law, 73 ASIL Proc. 301, 302 (1979)Google Scholar.

16 Cf de Mérode, , World Bank Admin. Trib. Judgment No. 1, para. 43 (1981)Google Scholar.

17 Ago, , Pluralism and the Origins of the International Community, 3 Ital. Y.B. Intx L. 3 et seq. (1977)Google Scholar; and his The First International Communities in the Mediterranean World, 53 Brit. Y.B. Int’l L. 213 et seq. (1982). Cf. Weil, , Lejudaisme et le developpement du droit international, 151 Recueil des Cours 253 (1975 III)Google Scholar.

18 Island of Palmas (Neth. v. U.S.), 2 R. Int’l Arb. Awards 831, 870 (Perm. Ct. Arb. 1928); cf. Anzilotti, D., Corso de diritto internazionale 39 et seq. (4th ed. 1955)Google Scholar.

19 1927 PCIJ, ser. A, No. 10, at 18.

20 Annex to UNGA Res. 2625 (XXV) (1970), reprinted in 65 AJIL 243 (1971), 9 ILM 1292 (1970).

21 “Each State has the right freely to choose and develop its political, social, economic and cultural systems.” Ibid.; cf. Art. 1 of both 1966 Covenants on Human Rights, Annex to UNGA Res. 2200 (XXI) (1966).

22 “[T]he importance of . . . developing friendly relations among nations irrespective of their political, economic and social systems or the levels of their development”; “States have the duty to co-operate with one another, irrespective of the differences in their political, economic and social systems . . .” (emphasis added). The very title of the declaration centers on the concepts of “relations” and “co-operation.”

23 The rules of diplomacy, the Court held, had proved “essential for the maintenance of peaceful relations between States” and were “accepted throughout the world by nations of all creeds, cultures and political complexions.” 1980 ICJ Rep. 3, 24, 42 (Judgment of May 24) (emphasis added). The institution of diplomacy had proved to be “an instrument essential for effective cooperation . . . enabling States, irrespective of their differing constitutional and social systems, to achieve mutual understanding”; the obligations thus laid upon states “are of cardinal importance for the maintenance of good relations . . . in the interdependent world of today . . . for the security and well-being of the . . . international community . . . , to which it is more essential than ever that the rules developed to ensure the ordered progress of relations between its members should be . . . respected.” 1979 ICJ Rep. 7, 19 (Order of Dec. 15); 1980 ICJ Rep. at 42, 43 (emphasis added).

24 1927 PCIJ, ser. A, No. 10, at 18.

25 Le Droit des gens, bk. II, ch. XII, §162 (Carnegie ed. 1916, trans, of 1758 ed.), original quoted in Marek, , Criminalizing State Responsibility, 14 Rev. Belge Droit Int’l 460, 484 (1978–79)Google Scholar: “Les peuples traitent ensemble en qualité d’hommes et non en qualité de Chrétiens ou de musulmans.”

26 P. Guggenheim, supra note 1, at 41: “fatalement un droit sécularisé et laique; il ne peut en être autrement si l’on tient compte de la variété des conceptions morales et religieuses qui sont celles des différentes sociétés constituant la communauté internationale”; cf. his Les Principes de droit international public, 80 Recueil des cours 1, 32–33 (1952 I).

27 See, in particular, the criticisms by Ago in Science juridique et droit international, 90 Recueil des cours 851 (1956 II); and Droit positifet droit international, 1957 Annuaire Français Droit Int’l 14.

28 Though not utterly opposed to use of the term “positive law” (droit positif) to cover the whole of the law in force, whether posé (i.e., enacted) or spontané, Ago would rather it were reserved, in accordance with its etymology, for jus positivum. Science juridique, supra note 27, at 60–61. However, the use of “positive law” in the broad sense of lex lata seems to have become an accepted commonplace. It is in this sense, for example, that the International Court of Justice, in North Sea Continental Shelf (FRG/Den.; FRG/Neth.), referred to the Truman Proclamation as “the starting point of the positive law on the subject.” 1969 ICJ Rep. 3, 32–33, para. 47 (Judgment of Feb. 20) (emphasis added); cf. id. at 37, para. 60.

29 Such terms as “legal conscience of states,” “awakening of conscience,” “universal conscience,” “common good of mankind” recur like a leitmotiv on practically every page of the International Law Commission’s work on the theories of jus cogens and international crimes.

30 In fact, even before the Second World War, concern to deny states the right to infringe—even by common accord—certain moral rules regarded as superior had led some writers to canvas the concept of peremptory norms or rules of jus cogens (for detailed background, see Suy, , The Concept of Jus Cogens in Public International Law, Carnegie Endowment for International Peace, 2 Papers & Proc. 17 (1967)Google Scholar). If the idea of rules standing “in a higher category” ( Mcnair, A., The Law of Treaties 214 (1961)Google Scholar) is thus not entirely new, it used to occupy merely a marginal place in doctrinal writings and, in the minds of its small number of advocates, was intended to be limited to the absolutely unchallenged rules of morality constituting, in Verdross’s words, “the ethical minimum recognized by all the states of the international community” (Forbidden Treaties in International Law, 31 AJIL 571, 574 (1937)). But it is more than a mere difference of degree that separates the modern theory of jus cogens from those first faint adumbrations.

31 On all these trends, see Dupuy, R.-J., Communaute Internationale et disparites de developpement, 165 Recueil des Cours 11 (1979 IV)Google Scholar.

32 See De Visscher, C., Positivisme et “jus cogens,” 75 Rev. Generale Droit Int’l Public 5 (1971)Google Scholar.

33 Ago, Fifth report on State responsibility [hereinafter cited as Ago Report], [1976] 2 Y.B. Int’l L. Comm’n, pt. 1, at 3, 32, UN Doc. A/CN.4/SER.A/1976/Add. 1 (pt. 1). Cf. the Commission’s Commentary, Draft articles on State responsibility, in Report of the International Law Commission on the work of its 28th session [hereinafter cited as ILC 1976 Report], id., pt. 2, at 1, 97, 102, UN Doc. A/CN.4/SER.A/1976/Add.l (pt. 2).

34 ILC 1976 Report, supra note 33, at 102.

35 C. De Visscher, supra note 32, at 9.

36 De Visscher, P., Cours général de droit international public, 136 Recueil des Cours 1, 107 (1972 II)Google Scholar.

37 ILC 1976 Report, supra note 33, at 92.

38 Id. at 97.

39 The Commission dismissed the idea “that there is one uniform regime of responsibility for the more serious internationally wrongful acts, on the one hand, and another uniform regime for the remaining wrongful acts, on the other.” Id. at 117. It is not certain that mere bipolarity is any longer likely to remain a feature of the distinction between norms: thus, one member of the Commission referred to the existence of “more or less important peremptory rules.” [1976] 1 Y.B. Int’l L. Comm’n 71, UN Doc. A/CN.4/SER.A/1976.

40 Hence, in the Commission’s work, such expressions as the following: some rules, “already existing, have acquired new vigour and more marked significance” (ILC 1976 Report, supra note 33, at 102); “the re-evaluation of rules that had existed since far earlier times” (Ago Report, supra note 33, at 53).

41 Draft articles on State responsibility, ILC 1976 Report, supra note 33, Art. 17, at 79, and Commentary, esp. at 80–87.

42 Id. at 86.

43 Thierry, H., Combacau, J., Sur, C., & Vallée, C., Droit international public 151 (3d ed. 1981)Google Scholar.

44 Reports of the International Law Commission on the second part of its 17th session and on its 18th session [hereinafter cited as ILC 1966 Reports], [1966] 2 Y.B. Int’l L. Comm’n 169, 248, UN Doc. A/CN.4/SER.A/1966/Add.l;and ILC 1976 Report, supra note 33, at 85. Hence, if certain rules in the Charter (not all, as we have seen) belong to the higher grade norms, that is due, not to their inclusion in an instrument supposed formally to be of superior normative status, but to their actual subject matter. Thus, the fact that Article 52 of the Vienna Convention on the Law of Treaties speaks of the threat or use of force “in violation of the principles of the Charter of the United Nations” (and not “in violation of the Charter of the United Nations”) derives partly from an intention to make the point that the prohibition of coercion is a rule of general international law whose peremptory character and even normativity are independent of its formal inclusion in the Charter. ILC 1966 Reports, supra, at 246–47.

45 “[T]hg majority of the general rules of international law do not have that [peremptory] character.” ILC 1966 Reports, supra note 44, at 248. “[J]us dispositivum remains the principle, jus cogens the exception. . . . T h e existence of a peremptory norm of general international law cannot be presumed.” Virally, Réflexions sur le “jus cogens,” 1966 Annuaire Français Droit Int’l 5, 25. “The concept of international crime must be restrictive.” Ago Report, supra note 33, at 90. “[I]t cannot be concluded that an international crime exists unless . . . two conditions are met.” ILC 1976 Report, supra note 33, at 120.

46 Reuter, P., La Convention de Vienne sur le droit des traités 21 (1970)Google Scholar.

47 Vienna Convention on the Law of Treaties, Art. 53, UN Doc. A/CONF.39/27 (1969), reprinted in 63 AJIL 875 (1969), 8 ILM 679 (1969).

48 Draft articles on State responsibility, ILC 1976 Report, supra note 33, Art. 19, at 75.

49 See infra para. 25.

50 Judge Lachs in U.S. Diplomatic and Consular Staff in Tehran, 1980 ICJ Rep. at 48 (sep. op. Lachs.J.).

51 Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space (1967), 18 UST, TIAS No. 6347, 610 UNTS 205, Art. 1; Agreement Governing the Activities of States on the Moon and other Celestial Bodies, UNGA Res. 34/68, Annex (1979), reprinted in 18 ILM 1434 (1979), Arts. 4 and 11; Convention on the Law of the Sea, UN Doc. A/CONF.62/122 and Corrs. 3 and 8 (1982), Art. 136, reprinted in 21 ILM 1261 (1982).

52 Report of the International Law Commission on the work of its 31st session [hereinafter cited as ILC 1979 Report], [1979] 2 Y.B. Int’l L. Comm’n, pt. 2, at 1, 156, UN Doc. A/CN.4/ SER.A/1979/Add.l (pt. 2). Coming 30 years as it did after the hesitance of the Reparations Opinion to allow international organizations full international personality, the Commission’s reluctance “needlessly” to place “organizations on the same footing as States” (ibid.) seems all the more telling in the light of the fact that the Court itself has since made a point of emphatically reiterating the impossibility of regarding an international organization as some sort of “super-State.” Interpretation of the Agreement of 25 March 1951 between the WHO and Egypt, 1980 ICJ Rep. at 89. Cf. de Mérode, World Bank Admin. Trib. Judgment No. 1, para. 28 (1981): “the differences between one organization and another are so obvious that the notion of a common law of international organizations must be subject to numerous and sometimes significant qualifications.”

53 ILC 1976 Report, supra note 33, at 119.

54 Cf. supra para. 17 and note 45.

55 The more so in that the concepts of jus cogens and international crime are themselves conceived of as essentially evolving. On jus cogens, see Vienna Convention, supra note 47, Art. 64, and ILC 1966 Reports, supra note 44, at 247–49; on international crime, see ILC 1976 Report, supra note 33, at 119.

56 See the example given infra note 68.

57 See, e.g., Lauterpacht, H., Règies générales du droit de la paix, 62 Recueil des Cours 95, 308 (1937 IV)Google Scholar. Lauterpacht repeated the idea in his 1953 report to the International Law Commission, [1953] 2 Y.B. Int’l L. Comm’n 90, 154 et seq., UN Doc. A/CN.4/SER.A/1953/Add.l. Cf. Sir Francis Vallat’s statement on behalf of the United Kingdom at the Vienna Conference on the Law of Treaties, Official Records of the First Session 420, para. 25, UN Doc. A/CONF.39/11 (1968).

58 See Dupuy, R.-J., Les Debats de Vienne sur les procedures du règlement, 1969 Annuaire Français Droit Int’l 70, 87–88 Google Scholar.

59 Regarding its draft articles on responsibility, the International Law Commission wrote: “In principle, derogations from all the rules in the present draft articles may be made by special agreement, subject to the existence of any rules of jus cogens.” ILC 1976 Report, supra note 33, at 93. Any reader applying this to the articles one by one will certainly have no easy task of evaluation.

60 It is precisely because it did not accept the provisions of Articles 53 and 64 that France refused to sign the Vienna Convention on the Law of Treaties. La Convention de Vienne sur le droit des traités, La Documentation française, Notes Et Etudes Documentaires, No. 3622, at 10(1969); cf. Deleau, , Les Positions françaises à la Conférence de Vienne sur le droit des traités, 1969 Annuaire Français Droit Int’l 23 CrossRefGoogle Scholar. Yet can these provisions nevertheless be opposed to it, either qua ordinary norms or qua peremptory norms of general international law?

61 P. Reuter, supra note 46, at 20.

62 This image corresponds to the Commission’s own presentation in its 1966 report: “Examples suggested included . . . ; . . . other possible examples.” ILC 1966 Reports, supra note 44, at 248.

63 Ago, , Introduction au droit des traités à la lumière de la Convention de Vienne, 134 Recueil des Cours 297, 324 (1971 III)Google Scholar.

64 For some the norms of higher rank include the rules on countering terrorism and hostage taking ( de Aréchaga, Jiménez, International Law in the Past Third of a Century, 159 id. at 1, 64 (1978 I)Google Scholar), sovereignty over natural resources ( Brownlie, I., Principles of Public International Law 513 (3d ed. 1979)Google Scholar), diplomatic inviolability (Ago, [1976] 1 Y.B. Int’l L. Comm’n 74). On the other hand, while the Commission had mentioned in this connection the principle of self-determination (ILC 1966 Reports, supra note 44, at 248), Ago did not refer to it in the lectures cited above (note 63). The Commission has made no secret of the fact that the categories of peremptory norms and essential obligations are both surrounded by uncertainties of many kinds (ILC 1976 Report, supra note 33, at 108–09; and 1979 id., supra note 52, at 115).

65 ILC 1976 Report, supra note 33, at 119–20. The opinions expressed hereon by the rapporteur (Ago Report, supra note 33, at 53; [1976] 1 Y.B. Int’l L. Comm’n 19, 57, 74, 89–90) and various other members of the Commission (id. at 67–68, 71) featured certain qualifications.

66 Thus, I. Brownlie, supra note 64, at 512, 612; Nguyen Quoc Dinh, P. Daillier, & A. Pellet, supra note 13, at 690; Dupuy, P.-M., Observations sur le “crime international de I’Etat,” 84 Rev. Générale Droit Int’l Public 449, 461 (1980)Google Scholar; and his Action publiqueet crime international de l’Etat, 1979 Annuaire Français Droit Int’l 539, 551, 553; cf. Marek, supra note 25, at 468.

67 Deleau, supra note 60, at 19.

68 As, for example, the provisions of General Assembly Resolution 1514 (XV) on decolonization, which the “international community” appears to regard as peremptory rules, whereas France refuses even to see them as ordinary rules of law. Id. at 17 and 19.

69 Reparation for injuries suffered in the service of the United Nations, 1949 ICJ Rep. 174, 181–82 (Advisory Opinion of Apr. 11).

70 Barcelona Traction, Light & Power Co. Ltd., 1970 ICJ Rep. 3, 33 (Judgment of Feb. 5).

71 See Bollecker-Stern, B., Le Préjudice dans la théorie de la responsabilité internationale 50 et seq. (1973)Google Scholar.

72 P.-M. Dupuy, Action publique, supra note 66, at 543: “caractéristique d’une situation generate de juxtaposition des souverainetés, puisqu’il enferme la responsabilite internationale dans un rapport bilatéral opposant l’obligation de l’un au droit subjectif de l’autre.”

73 1970 ICJ Rep. at 32.

74 ILC 1976 Report, supra note 33, at 99.

75 Nuclear Tests (Austl. v. Fr.), 1974 ICJ Rep. 253, 269–70 (Judgment of Dec. 20).

76 “[OJutlawing of acts of aggression, and of genocide, as also . . . principles and rules concerning the basic rights of the human person, including protection from slavery and racial discrimination.” 1970 ICJ Rep. at 32. Later in the same Barcelona Traction Judgment, however, the Court pointed out that “the instruments which embody human rights do not confer on States the capacity to protect the victims of infringements of such rights irrespective of their nationality.” Id. at 47. This passage is not easy to reconcile with the earlier one.

77 [1976] 1 Y.B. Int’l L. Comm’n 71.

78 1927 PCIJ, ser. A, No. 10, at 18.

79 De Visscher, , La Codification du droit international, 6 Recueil des Cours 325, 361–62 (1925 I)Google Scholar.

80 North Sea Continental Shelf, 1969 ICJ Rep. at 44.

81 Colombian-Peruvian asylum, 1950 ICJ Rep. 266, 278 (Judgment of Nov. 20); Fisheries (UK v. Nor.), 1951 ICJ Rep. 116, 131 (Judgment of Dec. 18).

82 Cf. 1 C. Rousseau, supra note 2, at 320; Akehurst, , Custom as a Source of International Law, 47 Brit. Y.B. Int’l L. 1, 24 (1974–75)Google Scholar; Jiménez de Aréchaga, supra note 64, at 30.

83 1969 ICJ Rep. at 42.

84 Id. at 43.

85 1970 ICJ Rep. at 32.

86 When the passages quoted from the North Sea Continental Shelf Judgment are reinserted in context, it will be seen that the Court by no means discounts the actual conduct of states, to which it in fact attaches, as it has always attached, decisive importance. Cf. 1969 ICJ Rep. at 41 and 43. As for that quoted from the Barcelona Traction Judgment, it refers to the possibility of claiming observance of a rule embodied in a quasi-universal treaty, and not to the possibility of creating, by such a treaty, obligations binding on all states.

87 Nahlik, , Droit dit “de Genève” et droit dit “de La Hay”: unicité ou dualité?, 1978 Annuaire Français Droit Int’l 27 Google Scholar.

88 1949 ICJ Rep. at 185.

89 Manin, , Le Juge international et la règle générale, 80 Rev. Générale Droit Int’l Public 7 (1976)Google Scholar.

90 Cf. Judge Alvarez in Asylum, 1950 ICJ Rep. at 293–94 (diss. op. Alvarez, J.).

91 See, e.g., Fisheries Judgment, 1951 ICJ Rep. at 30.

92 In 1976 the International Law Commission was still in certain places contrasting “general” international law to the “particular” international law concluded between two or more states, e.g., its 1976 Report, supra note 33, at 92; elsewhere, however, it used the term “general international law” to denote customary, as opposed to conventional, rules, e.g., id. at 80–81. Similarly, the expression “peremptory norm of general international law” in Article 53 of the Vienna Convention on the Law of Treaties is mostly construed as referring to rules of universal application, as opposed to rules of regional or bilateral scope. See, e.g., Virally, supra note 45, at 15.

93 1969 ICJ Rep. at 28, 37, 39, 40, 41, 43, 45.

94 Id. at 24, 28, 41.

95 Id. at 28, 38.

96 Id. at 42. The decision of June 30, 1977 of the court of arbitration in Delimitation of the Continental Shelf (France/United Kingdom) (Cmnd. 7438 (1978), reprinted in 18 ILM 397 (1979)) [hereinafter cited as 1977 Decision] also, though less frequently, uses the term “general international law” to indicate customary law (e.g., in para. 62).

97 1969 ICJ Rep. at 28; cf. p. 41. Sometimes the same significance is read into the passage where the Court refers to “general or customary law rules and obligations which, by their very nature, must have equal force for all members of the international community, and cannot therefore be the subject of any right of unilateral exclusion exercisable at will by any one of them in its own favour.” Id. at 38–39. It is clear, however, that this passage is solely aimed at precluding reservations to provisions that, though conventional as to form, are customary as to substance (cf. infra para. 39), and is therefore not concerned with the universally binding character of general rules as such.

98 Cf. Marek, , Le Problème des sources du droit international dans l’arrêt sur le plateau continental de la mer du Nord, 6 Rev. Belge Droit Int’l 44, 54 (1970)Google Scholar; Manin, supra note 89, at 44 et seq.; Jiménez de Aréchaga, supra note 64, at 28. Admittedly, in the Barcelona Traction Judgment, the Court, referring to the evolution of foreign investment protection law, was to observe: “Here as elsewhere, a body of rules could only have developed with the consent of those concerned” (1970 ICJ Rep. at 47); however, Jiménez de Aréchaga sees this, not as the reintroduction of some form of voluntarism into the theory of custom, but as merely a reference “to aggregate consent” (supra note 64, at 29).

99 Stern, La Coutume au coeur du droit international: quelques réflexions, in Mélanges Reuter, supra note 14, at 479. Cf. Jiménez de Aréchaga, supra note 64, at 29.

100 As far back as the 5.5. Wimbledon case, J. Basdevant spoke of a rule possessing “the dual quality of being both a conventional rule and a customary rule.” 1923 PCIJ, ser. C, No. 3–1, at 182.

101 Baxter, , Treaties and Customs, 129 Recueil des Cours 25, 73 (1970 I)Google Scholar.

102 Marek, supra note 98, at 72; Jiménez de Aréchaga, supra note 64, at 23, 27.

103 1969 ICJ Rep. at 41.

104 1977 Decision, supra note 96, para. 70.

105 1980 ICJ Rep. at 31 (emphasis added); cf. pp. 24 and 44; see also 1979 ICJ Rep. 7, 10, 20 (Order of Dec. 15). In its 1951 Advisory Opinion on Reservations to the Genocide Convention, the Court had already made a similar observation. 1951 ICJ Rep. 15, 23 (Advisory Opinion of May 28).

106 Legal Consequences for States of the Continued Presence of South Africa in Namibia, 1971 ICJ Rep. 16, 47 (Advisory Opinion of June 21); Fisheries Jurisdiction (UK v. Iceland), Jurisdiction of the Court, 1973 ICJ Rep. 3, 14 (Judgment of Feb. 2); Aegean Sea Continental Shelf (Greece v. Turkey), 1978 ICJ Rep. 3, 39 (Judgment of Dec. 19); Interpretation of the Agreement of 25 March 1951 between the WHO and Egypt, 1980 ICJ Rep. at 92, 95. Cf. awards in Beagle Channel, 17 ILM 645 (1978), para. 7, and German External Debts, 19 ILM 1370 (1980), para. 16.

107 Cf. Fisheries Jurisdiction (UK v. Iceland), Merits, 1974 ICJ Rep. 3, 23 (Judgment of July 25).

108 C. De Visscher, supra note 32, at 8: “est un ordre en puissance dans l’esprit des hommes; dans les réalités de la vie internationale elle en est encore à se chercher, elle ne correspond pas à un ordre effectivement établi.” On the international community as a “historical” reality and as a “mythical value,” see Dupuy, R.-J., Leçon inaugurale (Paris: College de France, 1980)Google Scholar.

109 Admittedly, it might be possible to place another construction on the silence of the Court. Perhaps it considered that the rules of diplomatic inviolability could validly be set aside or modified by two states in the context of their bilateral relations and that they comprise their own system of sanctions. If so, it would have been for reasons peculiar to the case at hand that the Court regarded it as inappropriate to mention jus cogens and international crimes, and not because of any reluctance to accept the actual principle of these theories.