LEGAL CONSEQUENCES OF THE SEPARATION OF THE CHAGOS ARCHIPELAGO FROM MAURITIUS IN 1965 (ADVISORY OPINION OF 25 FEBRUARY 2019), INTERNATIONAL COURT OF JUSTICE: HISTORICAL CUSTOMARY INTERNATIONAL LAW AND SELF-DETERMINATION IN THE COLONIAL CONTEXT.

• Author: Fraser, Angus

I INTRODUCTION

[S]hips which used to bring food stopped coming. We had nothing to eat. No medicine. Nothing at all. We suffered a lot. But then one day, a ship called Nordvaer came. The administrator told us we had to board the ship, leaving everything, leaving all our personal belongings behind except a few clothes... and when this was done, it was done in the dark. We boarded the ship in the dark so that we could not see our island... conditions in the hull of the ship were bad. We were like animals and slaves in that ship. People were dying of sadness in that ship.

Marie Liseby Elyse

Chagossian, Mauritian Delegation

Statement to the International Court of Justice

On 23 June 2017, the United Nations General Assembly ('UNGA') adopted Resolution 71/292,' requesting an advisory opinion from the International Court of Justice ('Court') on two questions relating to the legality of the decolonisation of Mauritius. These two questions were as follows.

(a) Was the process of decolonization of Mauritius lawfully completed when Mauritius was granted independence in 1968, following the separation of the Chagos Archipelago from Mauritius and having regard to international law, including obligations reflected in General Assembly resolutions 1514 (XV) of 14 December 1960, 2066 (XX) of 16 December 1965, 2232 (XXI) of 20 December 1966 and 2357 (XXII) of 19 December 1967?

(b) What are the consequences under international law, including obligations reflected in the above-mentioned resolutions, arising from the continued administration by the United Kingdom of Great Britain and Northern Ireland of the Chagos Archipelago, including with respect to the inability of Mauritius to implement a programme for the resettlement on the Chagos Archipelago of its nationals, in particular those of Chagossian origin?

On 25 February 2019, following oral hearings, the Court published its answer ('Opinion). In a 45 page opinion the Court (2) established its advisory jurisdiction, examined the existence of a customary right to self-determination between 1965 and 1968, and, having found that such a right existed, concluded that the way in which the decolonisation of Mauritius occurred violated that right.

This note analyses each of these distinct but telated aspects of the Court's Opinion. Part II provides the factual background to the Opinion. Part III addresses the basis upon which the Court established its jurisdiction. Part IV examines the Court's methodology in finding a customary right to self-determination and argues that the Court's application of the two-element test was unsatisfactory and more closely resembled the assertion', rather than the identification, of custom. Part V analyses the Court's application of the right to selfdetermination in the context of the decolonisation of Mauritius and the separation of the Chagos Archipelago. As a whole, while the Opinion answers the questions posed, the Court's analysis was confined and, at times, unclear. The Court also limited its consideration to selfdetermination in the colonial context, (3) perhaps forgoing an opportunity to develop the law of self-determination.

II BACKGROUND TO THE OPINION

The Chagos Archipelago lies approximately 2,200 kilometres north-east of Mauritius. It consists of islands and atolls, the largest of which is the island of Diego Garcia. (4) Between 1814 and 1965, the Chagos Archipelago, a dependency of Mauritius, (5) was administered by the United Kingdom ('UK'). (6) In February 1964, the United States of America ('US') expressed interest in building military facilities on the island of Diego Garcia. (7) On 29 June 1964, the UK, as the administering colonial power, began talks with Mauritius to seek the separation of the Chagos Archipelago in exchange for Mauritius' independence. (8) An agreement was reached for that purpose on 23 September 1965 at Lancaster House ('Lancaster House Agreement'). (9)

The UK subsequently established a new colony called the British Indian Ocean Territory, of which the Chagos Archipelago was a part. (10) On 30 December 1966, the UK and US entered into the Agreement concerning the Availability for Defence Purposes of the British Indian Ocean Territory, pursuant to which the UK undertook to take any 'administrative measures' necessary to meet the US's defence needs, including resettling the inhabitants of the Chagos Archipelago ('1966 Agreement'). (11) In the period between 1967 and 1973, the Chagossians living in the Chagos Archipelago were forcibly removed and, to this day, are forbidden from returning. (12)

1. The Lancaster House Agreement

   On 11 April 1979, Prime Minister Ramgoolam told the Mauritian Parliament that 'we had no choice' but to agree to the surrender of the Chagos Archipelago to the UK. (13) In the course of negotiating the Lancaster House Agreement, Mauritius' consistent position was that it preferred to lease the Chagos Archipelago to the UK in exchange for independence, instead of detaching and ceding it. (14) This led the UK to conclude that 'forcible detachment' was required. (15)

   Two meetings occurred on 23 September 1965. In the morning, Prime Minister Wilson met with then Premier Ramgoolam and gave him Hobson's choice, reminding him that Diego Garcia could be detached with or without the Premier's consent:

   ... in theory there were a number of possibilities. The Premier and his colleagues could return to Mauritius either with Independence or without it. On the defence point, Diego Garcia could either be detached by order in Council or with the agreement of the Premier and his colleagues. The best solution of all might be independence and detachment by agreement, although he could not of course commit the Colonial Secretary at this point. (16)

   Then, in the afternoon, Premier Ramgoolam and other Mauritian Ministers met with the UK Secretary of State at Lancaster House. Premier Ramgoolam agreed to the detachment of the Chagos Archipelago for independence in principle, (17) subject to terms. (18) The following day the UK announced that it was in favour of granting independence to Mauritius. (19) Terms were finalised (20) and, on 5 November 1965, the Governor of Mauritius 'confirmed agreement to the detachment of the Chagos Archipelago.' (21)

2. The Response of the International Community

   The Lancaster House Agreement evoked international condemnation. On 16 December 1965, the UNGA adopted Resolution 2066 (XX) (22) on the 'Question of Mauritius' expressing deep concern about the detachment of the Chagos Archipelago and urging the UK not to violate Mauritius' territorial integrity. (23) Resolution 2232 (XXJ) (24) followed, in which the UNGA reiterated that any attempt at the partial or total disruption of the territorial integrity of colonial territories and the establishment of military bases on those territories is 'incompatible with the purposes and principles of the Charter [of the United Nations]... and of General Assembly Resolution 1514 (XV).' (25)

   Criticism of the Lancaster House Agreement has continued since the 1970's. (26) Most recently, on 23 June 2017, the UNGA requested this advisory opinion from the Court.

   Ill THE ADVISORY JURISDICTION OFTHE COURT

   The Court was satisfied that it had jurisdiction to give the Opinion, notwithstanding objections by some participants. (27) It then considered arguments as to whether, in its discretion, it should nevertheless decline to answer the request. These arguments were also rejected.

   It was notably argued that the questions posed to the Court related to a pending bilateral dispute between Mauritius and the UK, and that to answer them would contravene 'the principle that a State is not obliged to allow its disputes to be submitted to judicial settlement without its consent.' (28) However, the Court was satisfied that, notwithstanding the potential repercussions for Mauritius' sovereignty, the questions put to it, as framed, concerned the UNGA's discharge of its functions relating to the decolonisation of Mauritius, not the resolution of a bilateral territorial dispute. (29) ' The Court reached this conclusion despite the UK's submission that the dispute over sovereignty was the 'real dispute' that motivated the request to the UNGA. (30) The Court's decision demonstrates the significance of careful drafting to the justiciability of questions asked of the Court in an advisory opinion. (31)

   In contrast, in the related Cbagos Marine Protected Area Arbitration between the UK and Mauritius, (32) the Arbitral Tribunal concluded that the Parties' dispute was 'at its core, a dispute over sovereignty' (33) and the true 'object of the claim' (34) was to bolster Mauritius' claim to sovereignty over the Chagos Archipelago. Since the issue of land sovereignty was found not to concern the interpretation or application of the United Nations Convention for the Law of the Sea (35) the Arbitral Tribunal lacked jurisdiction to adjudicate upon certain submissions made by Mauritius. (36)

   IV THE EXISTENCE OF CUSTOMARY INTERNATIONAL LAW

   The Court, having established its jurisdiction, proceeded to consider the questions posed. The first question required the Court to ascertain the 'nature, content and scope' (37) of the law of self-determination at the time of the decolonisation of Mauritius, and then decide, by that law, whether the decolonisation was lawful. The Court identified the relevant...