The oral hearings in the advisory proceedings concerning the Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965 took place at the ICJ last week. Readers will recall the two questions posed by the General Assembly in its request for an Advisory Opinion (Resolution 71/292) and the procedural and propriety issues raised by this case, as discussed by Marko, Dapo and Antonios – here, here and here. A host of States – and the African Union – participated in the proceedings and their voluminous written and oral statements/comments will surely keep interested scholars busy for a long time to come. In this post, I will try to restrict myself to the task of offering a few initial comments on the self-determination arguments made in relation to the first question (essentially, was the decolonization of Mauritius lawfully completed when it acceded to independence in 1968, following the detachment of the Chagos Archipelago?). For this purpose, I will focus on the claims made by the UK and Mauritius for the sake of brevity, and not because I agree with the UK’s contention that Mauritius is the ‘de facto claimant’ in this case (Transcript p. 36).
When approaching the claims and counter-claims concerning the Chagos Archipelago – or the British Indian Ocean Territory (‘BIOT’) – it is worth bearing in mind at least two important considerations. First, the UK is clearly on the wrong side of history as far as both the creation and maintenance of the BIOT are concerned. Secondly, the closest comparable case in the ICJ’s jurisprudence, the Western Sahara Advisory Opinion, is different in one key respect. The Western Sahara Opinion was sought while the General Assembly was actively engaged in a fraught and flawed attempt at decolonization and it was delivered when the crisis was still unfolding. In contrast, in the present proceedings, the ICJ has been invited to answer questions which not only require it to establish the legal significance of events which occurred largely between 1965-1968 but also to assess their present consequences. Undoubtedly, this is a difficult task and we shall have to wait and see whether the Court responds positively to the Request or whether it adopts a more non-committal approach, as it did in its Kosovo Advisory Opinion.
Self-determination and Customary International Law
The UK argued that the right of self-determination had not crystallized as a norm of customary international law (CIL) by either 1965 or 1968 (e.g. Transcript, p. 48). Specifically, it denied that the Colonial Declaration (GAR 1514 (XV)(1960)) generated any binding legal obligations as far as Mauritius’ decolonization was concerned. The 1960 Declaration proclaimed the core right – that ‘all peoples have the right to self-determination’ (para. 2) – while stating that: ‘Any attempt aimed at the partial or total disruption of the national unity and the territorial integrity of a country is incompatible with the purposes and principles of the [UN] Charter’ (para. 6). The UK claimed that the right of self-determination only acquired CIL status with the adoption of the Declaration on Friendly Relations (GAR 2625 (XXV)(1970). It relied on voting records, and the statements made, by State representatives, in the context of the development and adoption of these, and other, resolutions (and contemporaneous academic opinions) in support of its preferred interpretation.
Mauritius rejected this reading of history (e.g. Transcript pp. 45-47). It asserted that self-determination emerged as a CIL norm well before 1965. To this end, it carefully traced the way in which this entitlement evolved, from the 1950s onwards, through the General Assembly’s work in the context of decolonization and via the drafting of the International Covenants on Human Rights leading, Mauritius argued, to the conclusion that self-determination’s CIL status was confirmed by the adoption of the Colonial Declaration. Mauritius’ interpretation attracted the support of the other participating States and the African Union, save for the colonial power and the ‘forgetful’ United States (Transcript, p. 66).
The UK, evidently, placed considerable weight on the principle of inter-temporal law – that actions must be judged by reference to the law in force at the time they were undertaken – in an effort to sustain its claim that the detachment of the Chagos Islands from the Mauritian colonial unit did not breach the international law of the time. Readers will be familiar with the problem of pin-pointing the precise moment at which the established tests, endorsed by the Court in the North Sea Continental Shelf Cases and the Nicaragua Case, have been met and a norm has, definitively, achieved CIL status. But, as we all know, State practice can take many forms and there comes a time when decision-makers have to take a view about the balance of such matters, based on the available evidence and the purposive trajectory of international law.
There is a degree of plausibility in the contention that self-determination became custom with the adoption of the 1970 Declaration, especially when used to sustain of the remedial thesis that the BIOT itself qualifies as Non-Self-Governing Territory, despite the UK’s unfounded denial to the UN, back in 1965, that the Archipelago had its own permanent population – the Chagos Islanders. On this point see, e.g., R (Bancoult) v Secretary of State for Foreign and Commonwealth Affairs (No.1)  1 QB 1067, (para. 12) and Allen, The Chagos Islanders and International Law (Hart Publishing, 2014). However, the claim that self-determination only acquired customary status in 1970 is unpalatable when used solely for the purpose of defending the UK’s unqualified sovereignty claim.
While, in 1965, different perspectives certainly existed as to whether self-determination constituted CIL, does this mean that international law’s direction of travel, along with more recent declarations regarding self-determination’s erga omnes character and its peremptory status, can be overlooked? Obviously, clinical legal arguments cannot overcome the moral repugnance of colonialism. Moreover, although the Tribunal in the Chagos Marine Protection Area Arbitration Case decided that it did not have jurisdiction to adjudicate the question of sovereignty it is notable that Judges Kateka and Wolfrum, in their Concurring and Dissenting Opinion, were willing to find that the right of self-determination had entered into custom before 1970; that it was violated by the Archipelago’s excision from the Mauritian colonial unit; and they were receptive to Mauritius’ duress argument, too (paras. 70-79). While the UK rightly points out that the parties are bound by the Tribunal’s Award rather than the observations of those judges in the minority, it would be unsurprising if the members of the Court shared their reading of key historical events, notwithstanding the disputed interpretations offered by the main protagonists regarding certain aspects of this case.
Exercising the Right of Self-determination and Duress
The UK made a number of alternative arguments including the claim, in terms, that detachment amounted to an act of self-determination rather than a denial of it. The UK reasoned that the elected representatives of Mauritius were competent to cede a portion of Mauritian territory in return for certain benefits. And, if not, it contended that the Mauritian people, as a whole, exercised their free will in the 1967 General Election, in any event (Transcript, pp. 42-43). In response, Mauritius maintained that the subdivision of a colonial territory as an instance of self-determination could only occur pursuant to the freely expressed will of the people concerned rather than through their elected representatives. Mauritius argued that the 1967 general election was not sufficient for this purpose as the Archipelago had already been excised by then anyway (Transcript, pp. 49 and 54-55). This position is consistent with the modes of self-government set out in Resolution 1541(XV)(1960), which followed quickly on the heels of the Colonial Declaration, and the pivotal State practice.
Further, the UK’s faith in the validating effect of the 1965 Lancaster House Agreement ignores the unequal bargaining positions of the parties. An arrangement concluded between an Administering Power and one of its remaining Non-Self-Governing Territories is, by its very nature, liable to be the product of undue influence and, thus, inconsistent with the ‘sacred trust’ which the UN Charter imposed on Colonial Powers in relation to their colonial territories. In particular, Mauritius pointed out that its consent to detachment was vitiated by duress and, therefore, obtained in violation of the right to self-determination. The UK retorted that the Mauritian government accepted the lawfulness of detachment, both in 1965 and after independence, alluding to the fact that Mauritius only started to publicly demand retrocession in the 1980s (Transcript, p. 44).
International law only recognises claims of coercion in a narrow range of circumstances and, even then, it sets a high threshold for such a finding. As a result, Mauritius formulated its claim by reference to the ‘everyday meaning’ of duress (Transcript, p. 52) rather than recourse to the standard enumerated in the Article 52 of the Vienna Convention on the Law of Treaties, which Mauritius argued was inapplicable, as the Lancaster House Agreement was not a treaty. On its own this is not a particularly convincing argument but when it is interpreted in the light of paragraph 5 of the Colonial Declaration – which holds, in effect, that independence must not be fettered by conditions or reservations – it becomes a much more substantial claim. However, this does seem to mean that Mauritius must bear the burden of proving that detachment was indeed the price of Mauritian independence.
The UK made much of the 1965 Lancaster House Agreement in support of its consent claim (e.g. Transcript, pp. 30 and 45). Specifically, it pointed to the Chagos Arbitration Tribunal’s finding that it had been elevated to plane of international law once Mauritius acceded to independence, in 1968, thereby creating obligations for both parties (Award, para. 425). However, it is notable that, in its Award, the Chagos Tribunal relied heavily on Lancaster House Undertakings and the principle of estoppel rather than the 1965 Agreement, perhaps in response to Mauritius’ duress argument. This undercuts the UK’s argument on the issue of consent somewhat. I explored the 1965 Agreement’s character and the way that the Tribunal harnessed the principle of estoppel in my contribution to Allen and Monaghan (eds.), Fifty Years of the British Indian Ocean Territory: Legal Perspectives (Springer, 2018).
Uti Possidetis and Title to Territory
One of the difficulties for Mauritius flowed from its claim that these proceedings were about enabling the General Assembly to satisfy its general mandate to bring about the end of decolonization in a specific context. As a result, Mauritius had to avoid any arguments that would create the impression that this was really a bilateral dispute about territorial sovereignty. Consequently, it chose to argue that the case had nothing to do with title to territory (Transcript, pp. 78 and 80). It is notable that Mauritius invoked the principle of uti possidetis juris in pleadings in the Chagos Arbitration Case (Mauritius’ 2012 Memorial, pp. 108-109) but, in the present proceedings, it argued that colonial units were protected by the right of self-determination alone via an associated entitlement to territorial integrity (Mauritius’ Written Statement, pp. 216-219).
Uti possidetis juris creates a strong presumption that, as Malcolm Shaw noted, “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” (p. 97). The principle’s operation has attracted the use of metaphor. According to a Chamber of the ICJ, in the Frontier Dispute (Burkina Faso/Mali) Case:
‘… International law – and consequently the principle of uti possidetis – applies to the new State (as a State) not with retroactive effect, but immediately and from that moment onwards. It applies to the State as it is, i.e., to the ‘photograph’ of the territorial situation then existing. The principle of uti possidetis freezes the territorial title; it stops the clock, but does not put back the hands …’ (para. 30).
These observations led the UK to argue that it was only the exact moment of independence that mattered for the purpose of decolonization and, consequently, a colonial power was entitled to alter the territorial parameters of the colonial unit at any time prior to the achievement of independence (Transcript, p. 42).
The use of metaphor in this context is misleading and the UK’s argument is unsustainable. One of the concerns which led to the adoption of uti possidetis juris in Africa was the perceived need to maintain international stability and to obviate ‘fratricidal struggles’ during the process of decolonization by discouraging irredentist claims (Frontier Dispute Case, para. 20). Accordingly, it should be not interpreted as a momentary phenomenon and, at the level of principle, it is inconceivable that administering powers would be competent to dismember their colonial territories on the eve of independence, particularly where it would involve the creation of a new colony and the deracination of the population concerned. Even so, it is hard to take seriously Mauritius’ unorthodox argument that the issue of self-determination can be separated from the question of title to territory. Clearly, they are closely intertwined but does mean that this case should be properly characterized as a bilateral dispute? The exercise of the right to external self-determination will always have territorial consequences and so it is unlikely that this issue, on its own, would be enough to compel the Court to decline to answer the General Assembly’s questions.
Consequences and Resettlement
Mauritius argued that, in relation to the General Assembly’s second question – in short, what are the consequences of detachment for the UK’s ongoing administration of the Chagos Islands? – the right outcome would be for the Archipelago to be returned to Mauritius immediately (or at least within six months, Transcript, p. 63). But exactly what this means for the Chagossians is still unclear. The Request specifically refers to the issue of resettlement but Mauritius has published no resettlement plans, as yet. The moving video testimony of Liseby Elyse, delivered on the first morning of the proceedings, and the UK government’s well-documented callous disregard for the Archipago’s permanent inhabitants provide a glimpse of the huge human cost caused by the forced removal of the Chagossians’ from their ancestral homeland. However, it should not be forgotten that the Chagossians continue to experience chronic impoverishment in Mauritius and they have remained firmly at the bottom of Mauritian society since their arrival on the island all those years ago.