In 1965, three years before Mauritius was given its independence, the UK decided to separate the Chagos Islands from the rest of its then Indian Ocean colony. The Mauritian government claims this was in breach of UN general assembly resolution 1514, passed in 1960, which specifically banned the breakup of colonies prior to independence.
The Chagos archipelago was subsequently declared to be part of the British Indian Ocean Territory (Biot) from which, in 1971, most of the 1,500 islanders were deported. The largest island, Diego Garcia, was then leased to the US as a strategic airbase. The lease is due to be renegotiated by December 2014.
A legal battle, which begun more than two years ago, raised important questions about who has sovereignty over the Indian Ocean territory. Mauritian government officials believe it could lead to the unravelling of Britain’s disputed claim and the eventual return of the Chagos islanders.
Britain’s colonial-era decision to sever an Indian Ocean archipelago from Mauritius and turn it into a US military base will have to be justified before an international tribunal.