In May, the former inhabitants of the British overseas territory of the Chagos Islands won an important legal victory over the UK government. The Court of Appeal determined that the Chagos islanders, known as the Ilois or Chagossians, had been wrongfully denied the right to return to their homeland.

Ceded to the British by France in 1814, the Chagos Islands are located in the middle of the Indian Ocean. The archipelago is composed of six atolls and 2,300 low-lying islands, and the main economic activities carried out by its 2,000 or so inhabitants were the manufacture of copra (dried coconut), fishing and sugar cane cultivation.

In 1965, the British separated the islands from neighbouring Mauritius, which subsequently gained independence from the UK. They were then constituted as a separate colony--the British Indian Ocean Territory (BLOT). The following year, the UK signed a military agreement with the USA that allowed the latter to lease Diego Garcia (the archipelago's main island) for 50 years. The USA established a military base, which it used to monitor Soviet naval manoeuvres and for other intelligence-gathering activities, and arrangements were made for the local population to be removed.

By 1971, the inhabitants had all been resettled on the island of Mauritius. The British government paid the Mauritian government 3million [pounds sterling] in compensation and offered a further payment in 1982, even though, by then, Mauritius had sought to challenge the decision to create the BIOT. For the most part, the islanders failed to prosper in Mauritius, and many remain socially disadvantaged and economically marginalised.

A group of islanders, together with the UK Chagos Support Association, decided to challenge the government's removal of the original inhabitants. In November 2000, the Divisional Court ruled that the exclusion of an entire population from its homeland was unconstitutional. The then foreign secretary, the late Robin Cook, accepted that the islanders should be allowed to return to the outlying islands, although not to Diego Garcia.

However, the base has proved to be extremely valuable to the US military in its 'war on terror'. Four thousand US service personnel are still stationed there, and B52 and B2 bombers have flown missions to Afghanistan and Iraq from its airfields. Consequently, the British government has proved to be reluctant to respect the Divisional Court's decision. In 2004, it used an Order in Council to deny the islanders the right of return, but this was overturned by the High Court last year.

Under May's Court of Appeal ruling, the islanders will be allowed to return to the Chagos Islands but won't be allowed to resettle on Diego Garcia. While the government intends to petition the Law Lords directly to have the ruling overturned, legal experts have suggested that it's unlikely to be successful. So it looks as if the US military on Diego Garcia will have to get used to having neighbours.

Klaus Dodds is professor of geopolitics at Royal Holloway, University of London