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Published online by Cambridge University Press: 23 December 2019
In its Chagos Advisory Opinion, the International Court of Justice (ICJ) ruled that the UK's detachment of the Chagos Archipelago from the colony of Mauritius on the eve of independence constituted a violation of customary international law (CIL). This article analyses the Court's approach to establishing the emergence and content of the right to self-determination in this frustrated case of decolonisation. It goes on to examine the argument that self-determination's peremptory character has decisive consequences in this specific context—a contention which found favour with several judges in their Separate Opinions. The article explores the extent to which the claims and counterclaims, made during the advisory proceedings, turned on countervailing readings of not only the key sources of custom but also of the principle of inter-temporal law. The final sections consider the significance of the Chagos Opinion for the Chagossians, both in relation to the Archipelago's resettlement and for their outstanding appeal in the UK courts (where the European Convention on Human Rights performs a pivotal role).
This article evolved out of presentations delivered at events on the Chagos Advisory Opinion organised by the Lauterpacht Centre for International Law; the British Institute of International and Comparative Law; the Stockholm Centre for International Law and Justice; and the University of Queensland. I would like to thank the participants for their comments and suggestions. Special thanks to Thomas Burri, Craig Forrest, Robert McCorquodale, Anna Riddell-Roberts, Jamie Trinidad and Pål Wrange.
1 Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965 (Advisory Opinion) 25 February 2019 <https://www.icj-cij.org/en/case/169/advisory-opinions>.
2 The Court ruled, unanimously, that it had jurisdiction to give an Advisory Opinion in accordance with Art 65, UN Charter. It decided that it should not decline to answer the Request (12 votes to 2).
3 See Vine, D, Island of Shame: The Secret History of the US Military Base on Diego Garcia (Princeton 2009)Google Scholar. Allen, S, The Chagos Islanders and International Law (Hart 2014)Google Scholar; and S Allen and C Monaghan (eds), Fifty Years of the British Indian Ocean Territory: Legal Perspectives (Springer 2018).
4 Mauritius was listed as a Non-Self-Governing Territory in GA Res 66(I) (1946).
5 See Chagos Advisory Opinion (n 1) [108–112].
6 ibid [100–107].
7 BIOT Order in Council (1965) SI 1965/1920.
8 ‘Exchange of Notes between the UK and US Governments concerning the Availability for Defence Purposes of the British Indian Ocean Territory’ (30 December 1966) UKTS No 15 (1967) Cmnd 3231.
9 Most were transported to Mauritius although some were taken to Seychelles. This prohibition was implemented through the 1971 BIOT Immigration Ordinance.
10 See the ‘Report of the Select Committee on the Excision of the Chagos Archipelago (No 2/1983)’ (Mauritian Legislative Assembly).
11 (1982) 1833 UNTS 39.
12 Chagos Marine Protected Area (Mauritius v UK), Award (Annex VII LOSC Tribunal, Perm Ct. Arb 2015).
13 See their Concurring and Dissenting Opinion, ibid, [70–79].
14 Arts 2(3), 56(2) and 194(4), Award (n 12) [547]. The MPA remains in force as a matter of UK law. See R (Bancoult No 3) v Secretary of State for Foreign and Commonwealth Affairs (2018) UKSC 3.
15 Award (n 12) [535, 539–540 and 544].
16 GA Res 71/292 (22 June 2017).
17 To this end, art 73(e) required all administering States to report to the UN Secretary General on the conditions prevailing in their NSGTs. The General Assembly was quick to assume the responsibility for monitoring developments in these Territories; see Allen (n 3) 139–56.
18 However, the Court had no difficulty in finding the strong connections between these provisions and the subsequent the emergence of the right to self-determination. See Opinion (n 1) [147].
19 Transcript (3 September 2018) AM, CR 2018/20, 45–47.
20 See Mauritius’ Written Statement (1 March 2018) 187–228. The key resolutions included: 421(V)(1950); 545 (VI)(1952); 637A (VII)(1952); 738 (VIII)(1953); 837 (IX)(1954); 1188 (XII)(1957); and the Report of the Third Committee on the Draft International Covenants on Human Rights (1955) A/3077.
21 The International Covenants on Human Rights were endorsed in GA Res 2200A (XXI) (1966).
22 Transcript (3 September 2018) PM, CR 2018/21, 48.
23 ibid 45. The Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States provided: ‘By virtue of the principle of equal rights and self-determination of peoples enshrined in the Charter of the United Nations, all peoples have the right freely to determine, without external interference, their political status and to pursue their economic, social and cultural development […]’.
24 Art 13, UN Charter.
25 See eg Thirlway, H, The Sources of International Law (Oxford University Press 2014) 79–81Google Scholar; Harris, D and Sivakumaran, S, Cases and Materials on International Law (8th edn, Sweet & Maxwell 2015) 54Google Scholar. But see Lepard, B (ed), Re-examining Customary International Law (Cambridge University Press 2017)CrossRefGoogle Scholar.
26 See the Nuclear Weapons Advisory Opinion (1996) ICJ Rep 226 [70].
27 North Sea Continental Shelf Cases (Federal Republic of Germany v Denmark and Netherlands) (1969) ICJ Rep 3 [77].
28 Conclusion 6(2) of the International Law Commission's (ILC) Draft Conclusions on the Identification of Customary International Law (2018) provides that State practice may take the form of ‘conduct in connection with resolutions adopted by an international organization’, A/73/10. The accompanying Commentary acknowledges that ‘such practice contributes to the formation, or expression, of [CIL] rules’ [7]. This position was also taken by the International Law Association in its ‘Statement of Principles Applicable to the Formation of General Customary International Law’ (2000) 19.
29 See Judge Huber's treatment of this principle in the Island of Palmas Case (Netherlands/USA) (1928) 2 RIAA 829, 845.
30 Transcript (5 September 2018) AM, CR 2018/24, 14.
31 Transcript (3 September 2018) AM, CR 2018/20, 47.
32 See Allen (n 3) 176–97.
33 Quoted in Mauritius’ Written Statement (1 March 2018) 211. But see Crawford, J, ‘The General Assembly, the International Court and Self-determination’ in Lowe, V and Fitzmaurice, M (eds), Fifty Years of the International Court of Justice: Essays in Honour of Sir Robert Jennings (Cambridge University Press 1996) 585CrossRefGoogle Scholar.
34 Summers, J, ‘Decolonisation Revisited and the Obligation Not to Divide a Non-Self-Governing Territory’ (2018) 55 Questions in International Law 147, 156–7Google Scholar.
35 Mauritius’ argument in Chagos MPA Case, cited by Guatemala, Transcript (5 September 2018) AM, CR 2018/24, 35.
36 See eg South Africa, Transcript (4 September 2018) AM, CR 2018/22, 14. Mauritius proclaimed self-determination's peremptory character. However, it did not allege that this status had been attained by 1965–1968: Written Statement (1 March 2018) 211.
37 Transcript (4 September 2018) PM, CR 2018/23, 55–57.
38 ibid. See arts 53 and 64, Vienna Convention on the Law of Treaties (1969).
39 See Venzke, I, How Interpretation Makes International Law: On Sematic Change and Normative Twists (Oxford University Press 2012)CrossRefGoogle Scholar; and Bianchi, A, Peat, D and Windsor, M (eds), Interpretation in International Law (Oxford University Press 2015)CrossRefGoogle Scholar.
40 South West Africa (Ethiopia v South Africa and Liberia v South Africa) (Second Phase) (1966) ICJ Rep 6.
41 Transcript (3 September 2018) AM, CR 2018/20, at 65. See art 14 of the ILC's arts on Responsibility of States for Internationally Wrongful Acts (2001) (ARSIWA).
42 Transcript, ibid, 63.
43 However, a number of participants in the proceedings raised the issue of reparations and see the Separate Opinions of Judges Trindade and Sebutinde.
44 Transcript (3 September 2018) AM, CR 2018/20, 78 and 80.
45 Mauritius’ 2012 Memorial in the Chagos MPA Case, 108–109. According to Shaw, the customary principle of uti possidetis juris creates a strong presumption that, ‘new States will come to independence with the same boundaries they had when they were administrative units within the territory or territories of a colonial power’: Shaw, M, ‘The Heritage of States: The Principle of Uti Possidetis Juris Today’ (1996) 67 BYBIL 75, 97Google Scholar.
46 Mauritius’ Written Statement (1 March 2018) 216–219.
47 A construction that was consistent with the one advanced by Belize in this case. See Transcript (4 September 2018) AM, CR 2018/23, 23. Also see Belize's Written Statement (30 January 2018) 20–29.
48 For discussion of this concept see Western Sahara Advisory Opinion (1975) ICJ Rep 12 [32–33].
49 See Mauritius’ Written Comments (8 May 2018) 38–39. This view was echoed by the African Union, Transcript (6 September 2018) PM, CR 2018/27, 19.
50 Frontier Dispute (Burkina Faso/Mali) Case (1986) ICJ Rep 566 [30].
51 Transcript (3 September 2018) PM, CR 2018/21, 42.
52 Frontier Dispute Case (n 50) [20].
53 Chagos Advisory Opinion (n 1) [150].
54 ibid [152–3].
55 ibid [160].
56 ibid [150–153]. See the Western Sahara Opinion (n 48) [59].
57 Chagos Advisory Opinion (n 1) [172].
58 ibid. This conclusion was based on the Committee of Twenty-Four's assessment that real power remained with the UK government during this period: ibid [99].
59 Chagos Advisory Opinion [174].
60 ibid [177] (13 votes to 1).
61 ibid [180]. See the East Timor (Portugal v Australia) Case (1995) ICJ Rep 102 [29].
62 GA Res 2625(XXV) (1970).
63 Chagos Advisory Opinion (n 1) [178–179].
64 See eg Trinidad, J, Self-Determination in Disputed Colonial Territories (Cambridge University Press 2018) 13–16CrossRefGoogle Scholar.
65 Separate Opinion of Judge Robinson, Chagos Advisory Opinion (n 1) [77]. According to his key criteria a customary norm could graduate to jus cogens if it: (a) has been recognised and accepted by States as a whole without the need for a corresponding conventional obligation having been established; (b) has a moral and humanitarian character; (c) protects the fundamental values of the international community; and (d) has universal application.
66 ibid.
67 ibid [71–73]. This account was assisted by the conclusion that the right to self-determination had entered into custom by 1957, as a result of a series of resolutions which had been adopted between 1950 and 1957 [6–17]; see (n 20).
68 ibid [83 and 88].
69 ibid [89]. This view was also shared by Judge Trindade in his Separate Opinion. See arts 40 and 41(2), ARSIWA. In any event, States would be under a duty not to knowingly assist the UK in perpetuating its internationally wrongful act via art 16.
70 Judge Tomka observed, in his Separate Opinion, that the Court was silent about this matter [10].
71 Transcript (3 September 2018) AM, CR 2018/20, 70.
72 A study, sponsored by the UK government, concluded that resettlement was feasible; see R (on the Application of Hoareau and Bancoult) v Secretary of State for Foreign and Commonwealth Affairs [2019] EWHC 221 (Admin) [36–51]. However, this assessment was based on continued observance of the UK's treaty obligations to the US. Mauritius would not be bound by any such commitments.
73 Counsel for Mauritius, ibid, 72.
74 In the General Assembly, the Mauritian Prime Minister said the treatment meted out to the Chagossians by the UK ‘was akin to a crime against humanity’: GA/12146 (22 May 2019).
75 See D Vine, ‘The Impoverishment of Displacement: Models for Documenting Human Rights Abuses and the People of Diego Garcia’ (2006) 13 Human Rights Brief 21.
76 Mauritius’ Written Reply to Judge Gaya's Question, [5].
77 ibid [6].
78 The UK's Comments on the Mauritius’ Written Reply, [5 and 8]. Also see the US's Comments [4].
79 See Jeffery, L, Chagos Islanders in Mauritius and the UK (Manchester University Press 2011)CrossRefGoogle Scholar.
80 Chagos Advisory Opinion (n 1) [113–130].
81 ibid [181].
82 See the statement of the Minister of State for Foreign Affairs, House of Commons (26 February 2019) and the views expressed by the UK's representative in the General Assembly (22 May 2019) GA/12146. Also see T Burri, ‘In the Wake of the ICJ's Opinion in Chagos: Britannia Waives the Rules’ Völkerrechtsblog (9 July 2019) <https://voelkerrechtsblog.org/in-the-wake-of-the-icjs-opinion-in-chagos-britannia-waives-the-rules/>.
83 GA Res 73/295 (22 May 2019). It also called on all States to co-operate with the UN and to refrain from any action that would impede or delay the decolonisation of Mauritius. The voting record was 116 in favour and 6 against, with 56 abstentions.
84 Judge Tomka, Separate Opinion, Chagos Advisory Opinion (n 1) [1].
85 Judge Gaya, Separate Opinion, ibid [1].
86 ibid [5]. This discretion was acknowledged in the Western Sahara Opinion (n 48) [71].
87 Judge Gaya's Separate Opinion, Chagos Advisory Opinion (n 1) [6].
88 Judge Abraham's Separate Opinion, ibid. This analysis may have been prompted by the controversial arrangements devised for Mayotte in the Comoros Archipelago. See Trinidad, J, ‘Self-Determination and Territorial Integrity in the Chagos Advisory Proceedings: Potential Broader Ramifications’ (2018) 55 Questions in International Law 61, 65–7Google Scholar.
89 ibid, Separate Opinion.
90 See Allen (n 3) 271–82; and A Schwebel, ‘International Law and Indigenous Peoples’ Rights: What Next for the Chagossians’ in Allen and Monaghan (n 3) 319.
91 [1998] 2 SCR 217.
92 ibid [124].
93 GA Res 61/295 (2007). However, the Indigenous specific variant of this entitlement does not give rise to a presumptive right to independent statehood.
94 The Mauritian government has objected to the Chagossians’ claim of Indigeneity saying that they constituted a segment of the wider Mauritian people. See Report of the 17th session of the UN Working Group on Indigenous Populations (12 August 1999) E/CN4/Sub2/1999/19 [63]. South Africa referred to the Chagossians as an Indigenous people during the advisory proceedings. Transcript (4 September 2018) PM, CR 2018/22, 13.
95 See eg S Wiessner ‘Indigenous Sovereignty: A Reassessment in Light of the UN Declaration on the Rights of Indigenous Peoples’ (2008) 41 Vanderbilt Journal of Transnational Law 1141; and Åhrén, M, Indigenous Peoples’ Status in the International Legal System (Oxford University Press 2016)CrossRefGoogle Scholar.
96 See (n 72).
97 [2019] EWCA Civ 1254.
98 ibid [2].
99 (2013) 56 EHRR SE15.
100 Bankovic v Belgium (2001) 44 EHRR SE5, [71]; and Al-Skeini v UK (2011) 53 EHRR 18, [136–7].
101 Bankovic, ibid [71]; Al-Skeini, ibid, [138–139]; and Loizidou v Turkey (Preliminary Objections) (1995) 20 EHRR 99, [75].
102 Al Skeini, ibid [140]; and Chagos Islanders v UK (n 99) [73].
103 ibid, Chagos Islanders v UK, [65–75]).
104 (2007) 44 EHRR SE4.
105 The terms of art 4 of Protocol 1 are comparable to art 56(1).
106 Chagos Advisory Opinion (n 1) [180].
107 Emphasis added.
108 Quark Fishing (n 104) [73].
109 However, a UK court would have to consider the constitutional implications of CIL on this point. See R v Margaret Jones [2007] 1 AC 136. Moreover, it may have to rule on the validity of any attempt by the UK government to certify that the BIOT constitutes a British Overseas Territory. See Christian v The Queen [2007] 2 AC 400, [9–10] (Lord Hoffmann); and The Fagernes [1927] P 311, 324 (Atkin LJ).
110 Moreover, the Advisory Opinion could also be used to overcome the European Court's finding that the Chagossians could not qualify as victims for the purpose of the Convention's application, under art 34, because the vast majority had settled their claims and received compensation through the 1982 Mauritius–UK Agreement: Chagos Islanders v UK (n 99) [81].
