The UK has ignored a United Nations General Assembly deadline for Britain to withdraw from the Chagos Islands, part of the British Indian Ocean Territory (BIOT).

It refuses to allow the islands to be reunified with Mauritius or the islanders to return to their homes, from which the British government evicted them in the 1970s. The Mauritian prime minister, Pravind Jugnauth, branded the UK “an illegal colonial occupier.”

The Foreign Office insisted on Britain’s sovereignty over the islands, which it said “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 Chagos Islands are of geostrategic significance. Britain leases Diego Garcia, the largest island in the Indian Ocean archipelago, to the United States. The US uses the site to house one of its largest airbases, with 4,000 US as well as British troops, as a launching pad for its criminal operations in the Middle East.

Britain allowed the CIA to use Diego Garcia as a “dark site,” where it detained and tortured people and also refueled extraordinary rendition flights, recently extending the lease on the islands to 2036.

The UN meeting in May condemned Britain’s occupation of the Chagos Islands and endorsed February’s non-binding ruling by the International Court of Justice (ICJ), calling on the UK to relinquish its hold on the territory within six months (by November 22, 2019) to complete the process of decolonisation. The ICJ’s ruling implied that the UK’s leasing Diego Garcia to the US is also illegal.

The UN’s decision was overwhelming, with only the US, Hungary, Israel, Australia and the Maldives supporting Britain—reflecting Britain’s diplomatic isolation and the diminished stature of the US on the world arena.

The UK, determined to hold onto its remaining 14 colonial possessions and to support the US, which has 5, rejected the ICJ’s ruling and the UN’s order. It fears claims from the Mauritian government for compensation and the implications for other sovereignty disputes, including with Spain over Gibraltar and Argentina over the Falklands/Malvinas.

This is not the first time Britain has defied the UN. In February 2016, Britain rejected a UN human rights panel ruling that WikiLeaks founder Julian Assange, who sought asylum inside the Ecuadorean embassy in London due to his persecution by the Swedish and British authorities, had been subjected to “arbitrary detention.” This is in line with a broader assault, led by the US, on the institutional arrangements established in the aftermath of World War II viewed as an unacceptable constraint on the pursuit of predatory imperialist interests.

The Chagos Islands are situated halfway between Tanzania and Indonesia. For more than five decades, Britain has carried out one crime after another against the Chagossians, using every trick in the book—lying, ignoring court decisions, invoking Royal Prerogative and then covering up its actions.

The Chagossians’ struggle for their rights began more than 50 years ago, when the Labour government granted Mauritius independence in 1968—but only after separating the Chagos Archipelago from Mauritius, in breach of UN resolution 1514 passed in 1960 banning the breakup of colonies before independence.

The UK denied the 1,344 islanders their right to return to their homeland, and handed it over as a military base, free of local residents, to the US. The government signed a sordid deal with Washington—kept secret from both Parliament and the US Congress—granting Washington a 50-year lease on Diego Garcia in return for an $11 million discount on the US-made Polaris nuclear weapons system, which Labour had pledged to scrap when in opposition.

The UK forcibly evicted and deported the islanders to Mauritius and the Seychelles, another former British colony, where they have lived in impoverished conditions and where the Chagossians say they are subject to xenophobia and denied education and employment opportunities. Some were allowed into Britain.

None of the promises of support and compensation were kept. Many of the islanders were simply abandoned when they landed. The promised compensation payments arrived five years late and were soon eaten up by inflation. The islanders, as a condition of accepting Britain’s derisory offer of compensation in the 1980s, were required to renounce their right to return. When the money did arrive, the Chagossians received much less than reported figures, with many receiving little or no compensation to this day.

Investigative journalist John Pilger first brought their plight to the world’s attention with his film Stealing a Nation in 2004.

The islanders and their descendants in Britain, who now number about 3,500 and are mainly resident in Crawley, West Sussex, have campaigned for their rights against a conspiracy of silence, obfuscation, temporising and lies. The British government has even attempted to deport third-generation Chagossians on the grounds that though their grandparents had been entitled to UK residency, they are not. E-mails, released under Freedom of Information requests, show that they have faced a lengthy campaign in Crawley denying them social housing and putting pressure on them to leave the country, paralleling the Windrush scandal.

In 2009, Gordon Brown’s Labour government issued an order turning the Chagos archipelago into a “marine reserve,” aimed at making resettlement impossible and denying Mauritian fishermen the right to fish in the archipelago’s waters.

In 2010, WikiLeaks exposed the real reasons behind this, publishing a batch of secret cables from the British government in 2009, reassuring the Americans that “the former inhabitants would find it difficult, if not impossible, to pursue their claim for resettlement on the islands if the entire Chagos were a marine reserve.”

For this and so much else, Wikileaks’s founder Julian Assange earned the undying hatred of the British government.

After the WikiLeaks revelations, the Chagossians and later Mauritius began legal proceedings against the UK government, with Mauritius winning a ruling at The Hague that Britain had acted illegally over the Chagos Islands and criticising London for failing to consult over the marine reserve. This changed nothing. In 2016, after years of delays, the Foreign Office finally announced that Chagos islanders would not be given the right of return to resettle, arguing that the cost and US objections made it impossible.

The islands are close to some of the busiest shipping lanes in the world, with two-thirds of global petroleum exports traversing the Indian Ocean. India has for several years sought economic and, to a lesser extent, military expansion in and around the ocean, including creating military bases in Mauritius and the Seychelles. China’s Belt and Road Initiative has financed infrastructure in the littoral countries, including Gwadar port in Pakistan and its first overseas military base in Djibouti.

India, China, Japan, the US, Britain, France, Australia and Pakistan have competing and overlapping military and economic alliances. Marking a shift from its earlier focus on the Pacific, the US has renamed its regional military hub, the “Indo-Pacific Command.”