1 In paragraph 2 of its commentary on Article 5, the ILC observes that this Article, although cast in terms of an obligation, also expresses the correlative entitlement.

1 Memorial of Namibia, p. 10, para. 32.

2 Ibid., para. 33.

3 Memorial of Namibia, Vol. I, p. 65, para. 177, (emphasis supplied).

4 Counter-Memorial of Botswana, Vol. I, p. 84, para. 238.

5 CR 99/13, p. 57.

6 See the remarks of the Special Rapporteur, in discussing the comments by governments on the ILC Draft, 1964, that the ILC intended that evidence of subsequent practice indicating a “common understanding“should be taken as an “authentic interpretation comparable to an interpretative agreement” (The Vienna Convention on the Law of Treaties, Travaux Préparatoires, Dietrich Rauschning, ed.,1978, p.247, para. 18).

7 See United Nations Conference on the Law of Treaties, First Session, 26 March-24 May, 1968, 1969, p. 442, para. 29.

8 Indeed, English speaking delegations appeared content with the word “understanding”. Thus Australia and the United States had introduced an amendment which, while retaining the words “understanding”, sought to introduce the word “common” before it (United Nations Conference on the Law of Treaties, supra, p. 442, para. 32).

9 Waldock, H., Doc. A/CN.4/186 and Add. 1-7, “Sixth Report on the Law of Treaties”, 2 International Law Com. (1966), p. 99.Google Scholar

10 See Le Grand Robert de La Langue Franҫaise, 1992, defining “accord” as “État qui résulte d'une conformité ou d'une communauté de sentiments, de pensées, de volontés“; María Moliner, Diccionario de Uso de l'Espaňol, 1988, defining “acuerdo” as “conformidad de pareceres entre dos o más personas”.

11 Ian M. Sinclair, The Vienna Convention on the Law of Treaties, 1973, p. 71 (emphasis added).

12 Case concerning a dispute between Argentina and Chile concerning the Beagle Channel (1977), United Nations, Reports of International Arbitral Awards, Vol. XXI, p. 187, para. 169.

13 See, for example, Corfu Channel, I.C.J. Reports 1949, p. 25; Temple of Preah Vihear, I.C.J. Reports 1962, pp. 33-35; South Wesi Africa, I.C.J. Reports 1971, p. 22; Military and Paramilitary Activities in and against Nicaragua, I.C.J. Reports 1984, pp. 408-413.

14 Fitzmaurice, Sir Gerald, The Law and Procedure of the International Court of Justice, Vol. 1, 1986, p. 357 Google Scholar.

15 Ibid.

16 Ibid., p. 359 (emphasis added).

17 Counter-Memorial of Botswana, Vol. I, p. 85, para. 240.

18 Fitzmaurice, op. cit., p. 359.

19 P.C.I.J., Series A/B, No. 53, p. 46.

20 Counter-Memorial of Namibia, Vol. I, p. 40, para. 83.

21 Judgment, para. 63.

22 Memorial of Namibia, Vol. I, p. 9, para. 28.

23 Reply of Botswana, Vol. I, p. 55, para. 157.

24 Memorial of Botswana, Vol. Ill, Annex 15, p. 226, para. 2.

25 Counter-Memorial of Namibia, Vol. IV, Ann. 71, para. 7 (a). This conclusion emerged from correspondence between Trollope and Dickinson, Redman's successor, who came to a “gentleman's agreement” in which they agreed to let the issue rest in obscurity (ibid., para. 8 and Ann. 73, para. 4).

26 Counter-Memorial of Namibia, Vol. I, p. 47, para. 104.

27 Memorial of Botswana, Vol. Ill, Ann. 28, para. 3 (b); Counter-Memorial of Namibia, Vol. I, p.48, para. 104.

28 Memorial of Namibia, Vol. IV, Ann. 65, also noted in the Court's Judgment, para.59.

29 Counter-Memorial of Namibia, Vol. II, Ann. 24; Counter-Memorial of Namibia, Vol. I, pp. 42-44, paras. 87-90.

30 Counter-Memorial of Namibia, Vol. II, Ann. 26.

31 Ibid., Ann. 27.

32 Counter-Memorial of Namibia, Vol. I, pp. 26-27, para. 57, citing examples from Ian Brownlie, African Boundaries: A Legal and Diplomatic Encyclopaedia, 1979.

33 Botswana's reply to Judge Fleischhauer's Question 1.

34 Ibid.

35 Memorial of Botswana, Vol. I, p. 89, para. 205, citing Julius Hatschek, Outline of International Law, trans, by C. A. W. Manning, 1930, p. 130.

36 See Counter-Memorial of Namibia, Vol. II, Ann. 9.

37 IX Annuaire de l'lnstitut de droit international (1887-1888), p. 173.

38 Westlake, J., International Law, Pt. I, Peace, 1904, p. 141.Google Scholar Westlake points out that the older authorities had taken the middle line of the river as the true boundary in obedience to the Roman law relating to delimitation of properties, and that the thalweg was thought to have been first proposed at the Congress of Rastatt (1798-1799).

39 L.F. von Neumann, Grundriss Des Heutigen Europaischen Volkerrechtes, 3rd ed., 1885, p. 45 (tr.).

40 Pasquale Fiore, Le Droit International, trans, from the Italian by A. Chretien, 1890, p. 205. A later edition accentuates the consideration of flow by defining the thalweg as determined by “the median line of the current and following precisely the course of water with the most rapid flow” (1911 ed., p. 503, trans, by C. Antoine).

41 Westlake, supra, p. 141; see also p. 33, fn. 103 of Counter-Memorial of Namibia.

42 Counter-Memorial of Namibia, Vol. I, p. 19, para. 45.

43 Ibid., para. 46.

44 Ibid., p. 20, para. 47. See Supp. Rep, sec. 12.

45 Judgment, para. 85.

46 Memorial of Botswana, Vol. I, paras. 270-272.

47 Counter-Memorial of Namibia, Vol. I, p. 63, para. 141.

48 Map GSGS 3915 of 1933, Namibia Atlas Map IX; see also, Memorial of Namibia, Vol. I, p. 125, para. 305

49 Memorial of Namibia, Vol. I, p. 121, para. 294; see also Counter-Memorial of Namibia, p. 69, para. 155.

50 Memorial of Namibia, Vol. I, p. 123, paras. 298-299; Counter-Memorial of Namibia, Vol. I, p. 70, para. 156.

51 Counter-Memorial of Namibia, Vol. I, p. 75, para. 162.

52 On the “overwhelming support of the international community” for the doctrine of equitable utilization and the limitations of territorial sovereignty in relation to riparian boundaries, see M. Fitzmaurice, in Legal Visions of the 21st Century, Anthony Anghie and Garry Sturgess (eds.), 1998, pp. 428-436.

53 CR 99/10, p. 15, para. 18.

54 CR, 99/6, p. 22.

55 See Biodiversity Convention, 1992, Preamble, para. 3.

56 Counter-Memorial of Namibia, Vol. Ill, p. 34, para. 11.9.

57 Ibid., para. 11.2; Memorial of Botswana, Vol. I, p. 14, para. 32.

58 Biodiversity Convention, Preamble, para. 10; ibid., art. 2.

59 Ibid., Preamble, para. 14.

60 Gabćíkovo-Nagymaros Project, I.C.J. Reports 1997, p. 78, para. 140.

61 I.C.J. Reports 1969, pp. 48-53.

62 Oppenheim's International Law, Vol. I, Peace, Parts 2 to 4, Sir Robert Jennings and Sir Arthur Watts (eds.), 9th ed., 1992, p. 691.

63 M. F. Lindley, The Acquisition and Government of Backward Territory in International Law, 1926, p. 210; see also Sir Thomas Holdich, Political Frontiers and Boundary Making, 1916, pp. 96-97.

64 Ian Brownlie, African Boundaries: A Legal and Diplomatic Encyclopaedia, op. cit., pp. 8-9.

65 W.E. Hall, A Treatise on International Law, 8th ed., A.P. Higgins (ed.), 1924, p. 153, para. 38b.

66 Ibid., p. 154, para. 38b.

67 “For better or for worse, from now [1890] on the Caprivi era would be known as the ‘new course'” (J. A. Nichols, Germany After Bismarck: The Caprivi Era 1890-1894, 1958, p. 68).

68 See Donald Kagan, On the Origins of War and the Preservation of Peace, 1995, p. 110. For a discussion of the changes in foreign policy and their impact on colonial policy, see ibid., pp. 121 et seq.

69 Nichols, op. cit., p. 102, quoting Caprivi's speech during his first appearance in the Reichstag on May 12, 1890, a speech in which he disclaimed being himself a “colonial enthusiast”.

70 Emphasis added. Memorial of Botswana, Vol. II, Annex 9, p. 51 (Correspondence respecting the Negotiations between Great Britain and Germany relating to Africa, April to December 1890, No. 1).

71 The 1890 Treaty with Great Britain was signed simultaneously with the lapsing of the Reinsurance Treaty with Russia, a cornerstone of Bismarck's foreign policy. The 1890 Treaty evidenced the increased interest in the building up of colonial possessions. The policy of clarifying spheres of influence with Great Britain was a natural preliminary stage of this process, so far as Southern Africa was concerned.

72 See further A. J. P. Taylor, Germany's First Bid for Colonies: 1884-1885, 1938, p. 98.

73 Brownlie, op. cit., p. 3.

74 Ibid.

75 Gerald Blake et al (eds.), 1997, pp. xi-xii.

76 Burkina Faso v. Mali, I.C.J. Reports 1986, p. 554.

77 Ibid., p. 617, para. 116.

78 Ibid., para. 117.

79 Ibid., para. 149, quoting Continental Shelf (Tunisia/Libyan Arab Jamahiriya), I.C.J. Reports 1982, p. 60, para. 71.

80 I.C.J. Reports 1969, pp. 53-54.

81 Ibid., p. 82.

82 Blake, op. cit., p. 249.

83 Statute for Co-ordination of Investigation of the Lower Mekong Basin, 1957, supplemented in 1995 in much detail by the Agreement on Co-operation for the Sustainable Development of the Mekong River Basin, setting out a regime for even closer co-operation in regard to irrigation, hydropower, flood control, fisheries, timber floating, recreation and tourism, governed by the Mekong River Commission; see also, Gerald Blake, op. cit., p. 294.

84 I.C.J. Reports 1997, pp. 78-79, paras. 140-144.

85 See the Protocol on Specially Protected Areas to the Barcelona Convention for the Protection of the Mediterranean Sea against Pollution (1982) by which signatories pledged to improve the state of natural resources and natural sites in the Mediterranean Sea by establishing and managing protected areas in the region.

86 For the vast variety of approaches to this problem, classified under scientific responses, economic responses, institutional responses, moral responses, and legal implementation, see Lakshman D. Guruswamy and Jeffrey A. McNeely (eds.), Protection of Global Biodiversity: Converging Strategies, 1998.

87 For example, Agreement Concerning the Sovereignty over the Islands of Al-'Arabiyah and Farsi, and the Delimitation of the Boundary Line Separating the Submarine Areas between the Kingdom of Saudi Arabia and Iran (1968), prohibiting oil drilling operations within 500m of the boundary on either side. See, also, Treaty Between the Hungarian People's Republic and the Republic of Austria Concerning the Regulation of Water Economy Questions in the Frontier Region (1956). This agreement prohibits a State from planning or constructing hydraulic works in the frontier waters of its own territory without consulting the other State, and prohibits any effect that would decrease the supply of water to the other State. It established the Permanent Hungarian-Austrian Water Commission to oversee any planning and settle disputes.

88 For example, Convention Between the Government of the French Republic and the Government of the Spanish State on the Delimitation of the Continental Shelves of the Two States in the Bay of Biscay (1974).

89 For example, Agreement on Settlement of Maritime Boundary Lines and Sovereign Rights over Islands between Qatar and Abu Dhabi (1969), providing for equal rights of ownership and revenue sharing with respect to an oil field through which the boundary runs.

90 For example, Itaipu Treaty (1972) between Brazil and Paraguay by which the section of the river that borders the two countries is owned and closely managed and monitored by the respective governments.

91 For example, Agreement between the Kingdom of Sweden and the Union of Soviet Socialist Republics on the Delimitation of the Continental Shelf of the Swedish Fishing Zone and the Soviet Economic Zone in the Baltic Sea (1988), providing that, in the formerly disputed area, each party will have fishing rights in that part of the zone allocated to the other party.

92 For example, Treaty between the Republic of Trinidad and Tobago, and the Republic of Venezuela on the Delimitation of Marine and Submarine Areas (1990) by which Venezuelan ships and aircraft were granted the rights of transit passage through the strait located between Trinidad and Tobago.

93 For example, Convention Between the French Republic and the Federal Republic of Germany Concerning the Development of the Rhine between Strasbourg/Kehl and Lauterbourg/Newburgweier (1969); Treaty between the United States and Canada Relating to Co-operative Development of Water Resources Relating to the Columbia River Basin (1961); Agreement between Argentina and Uruguay Relating to the Utilization of the Rapids of the Uruguay River in the Area of Salto Grande (1946).

94 For example, Agreement between India and Sri Lanka on the Boundary in Historic Waters between the Two Countries and Related Matters (1974).

95 For example, Treaty between Chile and Peru for the Settlement of the Dispute Regarding Tacna and Arica (1929), by which Chile gave Peru an easement over sections of certain irrigation channels which pass through Chilean territory.

96 For example, Exchanges of Notes between the United Kingdom and France Constituting an Agreement Relating to the Boundary between the Gold Coast and French Sudan (1904) by which villages situated in proximity to the frontier shall enjoy rights to the use of arable and pasture lands, springs, and watering places on the other side of the border. Similar clauses were contained in agreements relating to the boundary between the Gold Coast and Ivory Coast (1905), and Southern Nigeria and Dahomey (1906).

97 For both of these, see the Uruguay River Agreement referred to above. This Agreement was supplemented by the Declaration on Water Resources (1971) signed by the two governments calling for the equitable and reasonable utilization of the river's water resources, and the prevention of pollution.

98 For another example of detailed joint management provisions, see the Treaty between the Kingdom of the Netherlands and the Federal Republic of Germany Concerning the Course of the Common Frontier, the Boundary Waters, Real Property Situated Near the Frontier, Traffic Crossing the Frontier on Land and via Waters, and Other Frontier Questions (1960), which creates a Permanent Boundary Water Commission, sub-commissions, and an arbitral tribunal to co-ordinate management and settle disputes.

99 CR 99/10, p. 16, para. 24

1 In Article III (2) of the 1890 Treaty the term is used in the genitive. That makes it read in German des Hauptlaufes dieses Flusses. For reasons of convenience, I quote the term in German in the nominative Hauptlauf dieses Flusses. *Of the District of Massachusetts, sitting by designation.