Britain Has No Sovereignty Over The Chagos Islands

Chagossians waged a week-long hunger strike in Trafalgar Square in July 2018

THE maritime law tribunal of the United Nations has ruled that Britain has no sovereignty over the Chagos Islands.

It criticised London for its failure to hand the territory back to Mauritius.

The judges’ decision confirms a ruling by the International Court of Justice (ICJ) and a vote in the UN General Assembly.

The Indian Ocean archipelago includes a US military base. The UK has said it will hand the islands back when they’re no longer needed for defence purposes.

In response to the ruling, a spokesperson for the British Foreign Office said: ‘The UK has no doubt as to our sovereignty over the British Indian Ocean Territory (BIOT), which has been under continuous British sovereignty since 1814. Mauritius has never held sovereignty over the BIOT and the UK does not recognise its claim.’

The panel of judges at the United Nation’s International Tribunal for the Law of the Sea (ITLS) explicitly criticised the UK’s failure to hand the territory over to its former colony, Mauritius, by December 2019, as earlier demanded by a near-unanimous vote at the UN’s General Assembly.

‘The judgement … is clear and unequivocal. Mauritius is sovereign over the Chagos Archipelago,’ Mauritius’s Prime Minister Pravind Jugnauth told the BBC.

An international lawyer representing Mauritius in its dispute with the UK called on the British government to move quickly to surrender control of the islands.

‘What this means for the UK is that if it is to have any credibility around the world on the rule of law and its global branding, it needs to move immediately to bring this lamentable situation to an end,’ said lawyer Philippe Sands.

He argues that the ITLS judges had opted to ‘punish’ Britain for ignoring an earlier ruling by the ICJ in The Hague.

Thursday’s ruling emerged from a relatively obscure legal dispute about ocean maps, fishing rights, and hidden reefs, as Mauritius sought to settle a dispute with another Indian Ocean island nation, the Maldives, over their maritime borders.

The Maldives – which supports the UK’s claim to the Chagos Islands – had insisted that the boundary question could not be resolved while sovereignty remained in dispute.

The ITLS judges rejected that argument.

The UK, which was the former colonial power in Mauritius, has repeatedly promised to hand control of the Chagos archipelago back to Mauritius once the islands are no longer needed for defence purposes.

Following a secret deal between the UK and the US governments in the 1960s, one of the larger atolls, Diego Garcia, became a strategic American military airbase.

‘The end of UK administration has no implications for the US military base at Diego Garcia, which Mauritius is committed to maintaining,’ Prime Minister Jugnauth confirmed on Thursday.

The UN voted to send the Chagos issue to the ICJ for an advisory opinion, which came down unanimously against the UK in 2019, declaring that Britain was in violation of international law and should immediately move to complete the process of ‘decolonisation’ in relation to Mauritius.

The ICJ’s advisory opinion has now been given a powerful endorsement by the ITLS.

The ruling should enable Mauritius to start settling its new maritime borders.

Elderly Chagossians have campaigned for decades to be allowed to return to live on the islands from which some of them were forcibly removed by British troops.

The maritime tribunal’s press statement says: ‘Conclusions on the first and the second preliminary objection.

‘With respect to the first objection, the Special Chamber considers that, whatever interests the United Kingdom may still have with respect to the Chagos Archipelago, they would not render the United Kingdom a State with sufficient legal interests, let alone an indispensable third party, that would be affected by the delimitation of the maritime boundary around the Chagos Archipelago,’ (paragraph 247).

The Special Chamber concludes that ‘the United Kingdom is not an indispensable party to the present proceedings’ (paragraph 248).

Accordingly, the first preliminary objection of the Maldives is rejected. Concerning the second objection, the Special Chamber considers that its ‘findings as a whole provide it with sufficient basis to conclude that Mauritius can be regarded as the coastal State in respect of the Chagos Archipelago for the purpose of the delimitation of a maritime boundary even before the process of the decolonisation of Mauritius is completed’ (paragraph 250).

In the Special Chamber’s view, ‘to treat Mauritius as such a State is consistent with the determinations made in the Chagos arbitral award, and, in particular, the determinations made in the Chagos advisory opinion which were acted upon by UNGA resolution 73/295’ (paragraph 250).

In the circumstances of the case before it, ‘the Special Chamber is satisfied that Mauritius can be regarded as the State with an opposite or adjacent coast to the Maldives within the meaning of article 74, paragraph 1, and article 83, paragraph 1, of the Convention and the concerned State within the meaning of paragraph 3 of the same articles’ (paragraph 251).

Accordingly, the second preliminary objection of the Maldives is rejected. Third preliminary objection: Requirement under articles 74 and 83 of the Convention.

International Court of Justice ruling in 2019:

Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965


On 22 June 2017, the General Assembly adopted resolution 71/292, in which, referring to Article 65 of the Statute of the Court, it requested the Court to render an advisory opinion on the following questions:

(a) Was the process of decolonisation 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?

Thirty-one Member States of the United Nations and the African Union filed written statements, and ten States and the African Union filed written comments on the written statements. Ten States and the African Union subsequently presented written comments on these written statements. Twenty one States and the African Union participated in the oral proceedings, which took place from 3 to 6 September 2018.

In its Advisory Opinion delivered on 25 February 2019, the Court concluded that ‘the process of decolonisation of Mauritius was not lawfully completed when that country acceded to independence’ and that ‘the United Kingdom is under an obligation to bring to an end its administration of the Chagos Archipelago as rapidly as possible’.

Before reaching this conclusion, the Court first addressed the question of whether it possessed jurisdiction to give the advisory opinion requested by the General Assembly.

Having established that it did have jurisdiction to render the advisory opinion requested, the Court examined the question, raised by a number of participants, as to whether it should nevertheless decline to exercise that jurisdiction as a matter of discretion.

It concluded that, in light of its jurisprudence, there were ‘no compelling reasons for it to decline to give the opinion requested by the General Assembly’.

After examining the factual circumstances surrounding the separation of the archipelago from Mauritius, as well as those relating to the removal of the Chagossians from this territory, the Court addressed the questions submitted to it by the General Assembly, having found that there was ‘no need to reformulate the questions submitted to it for an advisory opinion in the proceedings’.