International Court of Justice states that UK administration of Chagos Archipelago is unlawful

05/03/19

On 25 February 2019, the International Court of Justice (ICJ) delivered its Advisory Opinion on the legality of the United Kingdom’s colonial administration of the Chagos Islands (now part of the British Indian Overseas Territory). It determined, by a 13-1 majority, that the UK’s administration of the Chagos Islands is a continuing unlawful act, that the UK has an obligation to bring to an end its administration of the Chagos Islands “as rapidly as possible” and that all member States must cooperate with the United Nations to complete the decolonisation of Mauritius.

The ICJ had been asked by the United Nations General Assembly, on the initiative of Mauritius, whether these actions by the UK were lawful under international law. The issue at stake was whether the UK’s division in 1965 of one of its colonies into two separate territories - Mauritius and the Chagos Islands – was lawful in accordance with the right to self-determination under international law. The UK divided this colony in order to lease the main island of the Chagos Islands - Diego Garcia - to the United States for its military purposes. As a consequence of this lease, which has been renewed, the UK forcibly removed all the inhabitants of all of the islands of the Chagos Islands from their homes and sent them to Mauritius and other locations. They have never been allowed to return despite many actions before the UK courts. The substantial majority of the States, including Vanuatu, which appeared before the ICJ argued that the actions of the UK were unlawful.

While an Advisory Opinion is not directly legally binding on the UK or other States, it does represent a clear statement of international law by the highest international court. As such, the UK, and the US, will be under pressure to comply with this rule of international law. The Opinion is here.