This article was written while the author was Visiting Professor of Law at Northwestern University School of Law, Chicago. Special thanks are due to Mrs. Krystyna Obuchowicr. The author also wishes to express her gratitude to Prof. Thomas M. Franck and to Prof. Nissim Bar-Yaacov for their most valuable comments and suggestions. A short summary of this article was presented to a panel on Equity at the 1987 Annual Meeting of the American Society of International Law.

Publication of this article in the Israel Law Review was made possible by the generous support of the Israel B. Greene and Sara Mann Greene Fund for Equity Studies.

1 Frontier Dispute, Judgment, I.C.J. Reports, 1986, p. 554 at 567–568. The last sentence is a quote from Fisheries Jurisdiction, I.C.J. Reports, 1974, p. 1, at 33. On the various types of equity mentioned, see infra, sec. II(C)(2).

2 ibid., at 633.

3 ibid., at 662–663.

4 Rousseau, Ch., Droit international public, tome I Introduction et sources (Sirey, Pans, 1970) 399.Google Scholar

5 Visscher, Ch. de, De l'équité dans le règlement arbitral ou judiciaire des litiges de droit international public (Pedone, Pans, 1972) 3.Google Scholar

6 “Commutative Justice” and “Distributive Justice”, in The Compact Edition of the Oxford English Dictionary (1971, repr. 1982) vol. 1, pp. 486 and 771.

7 Degan, V. D., L'équité et le droit international (Nijhoff, The Hague, 1970) 2.Google Scholar

8 Janis, M. W., “The Ambiguity of Equity in International Law” (1983) 9 Brooklyn J. Int'l. L. 7, at 30.Google Scholar

9 Jenks, C. W., “Equity as a Part of the Law Applied by the Permanent Court of International Justice” (1937) 53 L.Q.R. 519, at 523.Google Scholar

10 Rosenne, S., “Equitable Principles and the Compulsory Jurisdiction of International Tribunals” in Festschrift für Rudolf Bindschedler (Stämpfli, Bern, 1980) 407.Google Scholar

11 Reuter, P., “Quelques réflexions sur l'équité en droit international” (1980) 15 Revue Belge de Droit International 165, at 167–169.Google Scholar

12 United Nations Convention on the Law of the Sea, U.N. Publication Sales No. E.83.V.5 (1983). On the relation between equitable sharing and the notion of Common Heritage of Mankind, see Shraga, D., “The Common Heritage of Mankind: The Concept and Its Application” (1986) 15 Annals of International Studies 45.Google Scholar

13 (1979) 18 I.L.M. 1434, at 1438. The article calls for the establishment of an international regime with the purpose of, inter alia, achieving “an equitable sharing by all States Parties in the benefits derived from” the natural resources of the moon.

14 “In using frequency bands for space radio services Members shall bear in mind that radio frequencies and the geostationary satellite orbit are limited natural resources, that they must be used efficiently and economically so that countries or groups of countries may have equitable access to both in conformity with the provisions of the Radio Regulations according to their needs and the technical facilities at their disposal” (the “orbit-spectrum” resource), TIAS No. 8572, vol. 28, part 3, p. 2497, at 2529 (1976–77). See also Grove, S., “The Geostationary Orbit: Issues of Law and Policy” (1979) 73 Am. J. Int'l L. 444.CrossRefGoogle Scholar

15 (1969) 8 I.L.M. 679, at 696: “If the ground [for denouncing or suspending a treaty] relates solely to particular clauses, it may be invoked only with respect to those clauses where:…(c) continued performance of the remainder of the treaty would not be unjust…”

16 (1975) 14 I.L.M. 1292, at 1294: Section V deals with peaceful settlement of disputes, and it lays down, inter alia, that the parties “will endeavour in good faith and a spirit of cooperation to reach a rapid and equitable solution on the basis of international law”. The inclusion of this example is without prejudice to the question as to the legal effect of this Declaration.

17 International Law Association, Report of the Fifty-Second Conference, Helsinki (1966) 484, at 486–494. See also Resolution of the Institut de Droit International (Salzburg session) (1961) 49 Annuaire de l'Institut de Droit International vol. II, pp. 370–373.Google Scholar

18 U.N.G.A. Resolution 3201 (S–VI), May 1st, 1974, (1974) 13 I.L.M. 715; U.N.G.A. Resolution 3202 (S–VI), May 1st, 1974, (1974) 13 I.L.M. 720; U.N.G.A. Resolution 3281 (XXIX), December 12, 1974, (1975) 14 I.L.M. 251. Among the recent publications on this subject, see in particular Oppermann, T. and Petersmann, E. U. (eds.), Reforming the International Economic Order, Tübinger Schriften zum internationalen und europäischen Recht, vol. 1 (Duncker & Humbolt, Berlin, 1987).Google Scholar

19 Printed in (1986) 33 Netherlands Int'l L.R. 326.

20 52 Consolidated Treaty Series (Parry) 243, Article 6 (at 250), and Article 7 (at 252).

21 11 Reports of International Arbitral Awards 233, Article V, at 234.

22 The compromis was concluded in 1892, and the award was given in 1895. For text of compromis, see 176 Consolidated Treaty Series (Parry) 352, Article III (at 353).

23 1 R.I.A.A. 309, Article 1.

24 6 R.I.A.A. 9 (the agreement), 173 (the award).

25 6 R.I.A.A. 1819.

26 United Nations, Systematic Survey of Treaties for Pacific Settlement of International Disputes, 1928–1948 (1949) 435, at 440.Google Scholar Compare with European Convention for Pacific Settlement of Disputes, 1957, Article 26 (1959) 320 United Nations Treaty Series 243.

27 Statute of the P.C.I.J. and of the I.C.J., Article 38; Protocol to the Charter of the Organization of African Unity on the Commission of Mediation, Conciliation and Arbitration, Article 30, (1964) 3 I.L.M. 1116.

28 I.C.J. Reports, 1982, p. 18, at 21.

29 I.C.J. Reports, 1985, p. 13, at 16.

30 Ibid., at 18, 19.

31 Ibid., at 38, 57.

32 See e.g., the following articles on the problem de lege ferenda: Weiss, E. Brown, “Conservation and Equity Between Generations” in Contemporary Issues in International Law: Essays in Honour of Louis B. Sohn, Buergenthal, T., ed. (Engel, Kehl, 1984) 245Google Scholar; P. S. Thacher, “Equity Under Change”, and Weiss, E. Brown, “Inter-generational and Inter-temporal Equity” in Proceedings of the Annual Meeting of the American Society of International Law (1987)Google Scholar forthcoming.

33 P.C.I.J., Series A/B, No. 70, at 76–77.

34 I.C.J. Reports, 1956, p. 75. The tribunal had mistakenly used the expression “ex aequo et bono”, which generally requires the agreement of the parties in order that a tribunal may be authorized to decide accordingly, since that expression may also imply a decision against the legal rule; see infra.

35 50 International Law Reports 18.

36 I.C.J. Reports, 1969, p. 3.

37 Ibid., at 51, 53.

38 Ibid., at 51, 54.

39 Ibid., at 52, 54.

40 (1979) 18 I.L.M. 397.

41 Supra n. 28.

42 Case Concerning Delimitation of the Maritime Boundary in the Gulf of Maine Area (Canada/U.S.A.), I.C.J. Reports, 1984, p. 246. This decision dealt with the establishment of a single line to delimit both the continental shelf and the 200-line exclusive fishery zone.

43 Supra n. 29. For a fascinating analysis of the various delimitation cases, see Weil, P., Perspectives du droit de la délimitation maritime (Pedone, Paris, 1988).Google Scholar

44 The Barcelona Traction, Light and Power Company, Limited (New Application: 1962) (Belgium v. Spain), Second Phase, I.C.J. Reports, 1970, p. 1.

45 Ibid., at 84–86.

46 Fisheries Jurisdiction case (U.K. v. Iceland) Merits, I.C.J. Reports, 1974, p. 1. Fisheries Jurisdiction case (Federal Republic of Germany v. Iceland), Merits, I.C.J. Reports, 1974, p. 174.

47 Supra n. 1.

48 See, e.g., Degan, supra n. 7, at 25–39; Sohn, L. B., “Arbitration of International Disputes ex aequo et bond” in Sanders, P. (ed.)., International Arbitration-Liber Amicorum for Martin Domke (Nijhoff, The Hague, 1967) 330CrossRefGoogle Scholar; Sohn, , “The Role of Equity in the Jurisprudence of the International Court of Justice” in Dutoit, and Grisel, (eds.), Mélanges Georges Perrin (Lausanne, 1984) 303, at 306–308Google Scholar; Cheng, B., “Justice and Equity in International Law” (1955) 8 Current Legal Problems 185, at 202–211CrossRefGoogle Scholar; Grauer, C., “The Role of Equity in the Jurisprudence of the World Court” (1979) 37 U. Toronto L.R. 101, at 102 ff.Google Scholar; Scheuner, V., “Decisions ex aequo et bono by International Courts and Arbitral Tribunals” in Sanders, P. (ed.), International Arbitration - Liber Amicorum for Martin Domke (1967) 275.CrossRefGoogle Scholar Y. Dinstein distinguishes among the five following forms of interplay between international law and justice: “Justice may be detected or found (i) behind international law; (ii) through international law; (iii) within international law (infra legem); (iv) outside international law (praeter legem): or (v) in contradiction to international law (contra legem)”: see Dinstein, Y., “The Interaction of International Law and Justice” (1986) 16 Is. Yrbk. on Human Rights 9, at 29.Google Scholar P. Weil, in his analysis of the continental shelf delimitation cases, makes a distinction between “équité correctrice et équité autonome”, supra n. 43, at 179, and S. Bilge considers that la nouvelle fonction des principes équitables entant que règle coutumière prend sa place entre la fonction de l'équité infra legem et celle de l'équité praeter legem “, which, in his opinion, is a “fonction… modificatrice du droit existant”: Bilge, S., “Le nouveau rôle des principes équitables en droit international” in Festschrift für Rudolf Bindschedler (Stāmpfli, Bern, 1980) 105, at 127.Google Scholar

49 Frontier Dispute, supra n. 1, at 567–568.

50 B. Cheng, supra n. 48, at 204.

51 See, in particular, Grauer, supra n. 48. According to P. Weil, “Du Droit à l'ex aequo et bono, en passant par l'équité, ily a un continuum, sans distinctions tranchées”, supra n. 43, at 179.

52 Supra n. 34.

53 The S.S. Wimbeldon, P.C.I.J., Series A, No. 1, at p. 32 (1923).

54 Frontier Dispute, supra n. 1, at 633.

55 Akehurst, M., “Equity and General Principles of law” (1976) 25 I. & Comp. L. Q. 801, at 804, 806.CrossRefGoogle Scholar

56 I.C.J. Reports, 1949, p. 4.

57 Ibid., at 22.

58 Supra nn. 28, 29, 36, 40, 42.

59 Ch. Rousseau, supra n. 4, at 413. See also Grauer, supra n. 48. See also Frontier Dispute, supra n. 1, at 567.

60 L. B. Sohn (1967), supra n. 48, at 332.

61 For a discussion of the various opinions, see Degan, supra n. 7, at 30–33. See also Salam, G. Abdel, “L'équité comme méthode d'interprétation du droit international” (1973) 29 Revue Egyptienne de Droit International 233, at 242Google Scholar, who is of the opinion that no special authorization is needed.

62 See Ch. de Visscher, supra n. 5, at 12; Grauer, supra n. 48; Munkman, A.L.W., “Adjudication and Adjustment – International Judicial Decisions and the Settlement of Territorial and Boundary Disputes” (1972–1973) 46 Br. Y.B. Int. L. 1, at 14.Google Scholar

63 However, according to Kenneth R. Simmonds, one part of the Award in the Rann of Kutch case was decided ex aequo et bono despite the lack of an express authorization to that effect: see Simmonds, K. R. in “Transcript of Proceedings of a Roundtable” (1987) 22 Tex. Int. L. J. 151.Google Scholar In fact, the Chairman based a part of his decision on “the paramount consideration of promoting peace and stability in this region”: 17 R.I.A.A. 571.

64 Supra n. 36 at 47–48.

65 Supra n. 33 at 76.

66 M. Janis, supra n. 8, at 33–34; C. W. Jenks, supra n. 9, at 523.

67 Ch. de Visscher, supra n. 5, at 7.

68 V. D. Degan, supra n. 7, at 17. In a personal letter, Professor Marc Janis has suggested a most interesting explanation to this difference of opinions. He queries whether it might stem from the different municipal law views of the nature of equity: it “could be that Jenks (following Hudson) may be thinking of equitable rules in the fashion of Anglo-American Law (albeit drawing equitable rules out from many different legal systems), while Degan could be taking a civilian equity-as-extraordinary-power view of the notion…” The author wishes to express her thanks to Prof. Janis for this interesting remark.

69 M. Akehurst, supra n. 55, at 810.

70 Ibid., at n. 49.

71 Supra n. 33, at 77.

72 Simpson, J. L. and Fox, H., International Arbitration: Law and Practice (Stevens, London, 1959) 136.Google Scholar

73 (1937) 40 Annuaire de l'Institut de Droit International 271. This opinion seems to be shared by Ch. de Visscher, supra n. 5, at 5.

74 Schachter, O., International Law in Theory and Practice, General Course in Public International Law, 178 Hague Academy Recueil des Cours, 9–396, at 82 (1982–V).Google Scholar

75 B. Cheng, supra n. 48, at 189.

76 Ibid., at 201–202.

77 Ch. de Visscher, supra n. 5, at 27fT., 46ff.

78 P. Reuter, supra n. 11, at 165.

79 Frontier Dispute, supra n. 1, at 633. The quote within the quote is from the North Sea Continental Shelf decision, supra n. 36 at 49.

80 Ch. de Visscher, supra n. 5, at vii.

81 Supra n. 34.

82 Supra n. 15.

83 Supra n. 19, Article 3; see also Article 9.

84 Supra n. 36, at 52, 54.

85 Supra n. 40, at 426, 455; supra n. 28, at 91; supra n. 42 at 335–337; supra n. 29, at 43–46. See also Blecher, M. D., “Equitable Delimitation of Continental Shelf” (1979) 73 Am. J. Int'l L. 60, at 73–77.CrossRefGoogle Scholar

86 Supra n. 19, Article 8.

87 Supra n. 44.

88 For a most interesting analysis of the qualities of justice as represented by images, see Curtis, D. E. and Resnik, J., “Images of Justice” (1987) 96 Yale L. J. 1727, at 1764.CrossRefGoogle Scholar Concluding the discussion of a late fifteenth-century fictitious dialogue written by Battista Fiera, an Italian doctor and humanist, about how to depict Justice, the authors state: “In the dialogue we can find our hopes that justice, as depicted, simultaneously be attuned to individual nuances and be even-handed; that objectivity and subjectivity both be present; that justice know all that is needed but not know that which might corrupt or unfairly influence; that justice be rigorous in its equality yet ‘now and then’ relax in compassion…”

89 Lauterpacht, E., “Equity, Evasion, Equivocation and Evolution in International Law” in Proceedings and Committee Reports of the American Branch of the International Law Association (1977–1978) 33, at 43.Google Scholar

90 Lalande, A., Vocabulaire technique el critique de la Philosophie (Pans, 9th ed., 1962) 295.Google Scholar

91 Dictionnaire de la terminologie du droit international (Sirey, Pans, 1960) 260

92 See the dissenting opinions by Judges Gros and Oda and Judge ad hoc Evenson in the Case Concerning the Continental Shelf (Tunisia/Libya), supra n. 28, at 143–323; the dissenting opinion of Judge Gros in the Gulf of Maine Delimitation case, supra n. 42, at 360–389, in particular 379–380; dissenting opinions by Judges Mosler, Oda and Schwebel in the Case Concerning the Continental Shelf (Libya/Malta), supra n. 29 at 114–187; Friedman, W., “The North Sea Continental Shelf Cases – A Critique” (1970) 64 Am. J. Int'l L. 229–240CrossRefGoogle Scholar; M. D. Blecher, supra n. 85; Pirotte, O., “La notion d'équité dans la jurisprudence récente de la Cour Internationale de Justice” (1973) 77 Revue Générale de Droit International Public 92–135Google Scholar; Decaux, E., “L'arrêt de la Cour Interna tionale de Justice dans l'affaire du Plateau Continental (Tunisie/Libye) – Arrêt du 24 février 1982” (1982) 28 Annuaire Français de Droit International 357–391CrossRefGoogle Scholar (“Cette incertitude radicale sur les motivations de l'arrêt transforme le raisonnement juridique en une sorte d'alchimie” – on p. 391); Decaux, , “L'arrêt de la Cour Internationale de Justice dans l'affaire du Plateau Continental (Libye/Malte) – Arrêt du 3 juin 1985” (1985) 31 Annuaire Français de Droit International 294–323CrossRefGoogle Scholar (“En fait, la Cour ne peut fournir qu 'une justification vague à une solution artificielle” – on p. 306); Varsey, L. De and Varsey, M. C. De, “The World Court Decision in the Canada-United States Gulf of Maine Seaward Boundary Dispute: A Perspective From Historical Geography” (1986) 18 Case Western Reserve J. Int'l L. 415, at 429ff.Google Scholar Judge Oda expressed his disapproval in strong words:

93 M. Akehurst, supra n. 55, at 811.

94 Ch. Rousseau, supra n. 4, at 403–404.

95 E. Lauterpacht, supra n. 89, at 46.

96 M. Akehurst, supra n. 55, at 813ff; O. Pirotte, supra n. 92, at 134; M. W. Janis, supra n. 8, at 33.

97 L. B. Sohn (1967), supra n. 48, at 333.

98 Supra n. 29, at 39.

99 B. Cheng, supra n. 48, at 211.