In 2024, the United Kingdom agreed to possibly one of the worst real estate deals in recorded history. It agreed to give Mauritius, a small country in the Indian Ocean, ownership of the Chagos Islands, home to the Anglo-American military base in Diego Garcia. In exchange, the U.K., which has owned the islands for more than 200 years, will pay Mauritius almost £34 billion over the next 99 years to rent Diego Garcia.
The windfall is such for Mauritius that 81% of its people will soon stop paying income tax. Worst yet, the United States, which has a clear interest in securing the future of the base at Diego Garcia, has given its blessing to the deal, despite the fact that it could fatally compromise the military use of the Chagos Islands.
But why did the U.K. agree to pay a banana republic for the privilege of giving it territory? Is there any reason, moral or legal, that it should do so?
As my colleagues’ and my previous writing for the British think tank Policy Exchange demonstrates decisively, there is no basis whatsoever for this deal. To understand the importance of the Chagos archipelago, one can simply look at a map of Asia. Located in the Indian Ocean south of the Maldives, the Chagos Islands occupy one of the most strategically important locations in the world. The U.S. has used Diego Garcia to protect the flow of oil from the Persian Gulf, project power in Asia after the loss of bases in southern Vietnam, and intercept signals intelligence.
During the first Gulf War, 800,000 short tons of bombs were dropped from Diego Garcia-based bombers. During the war in Afghanistan, Diego Garcia was used to launch 650 attacks against al Qaeda and the Taliban regime. In any future conflict involving the U.S. in Asia or the Middle East, Diego Garcia will play a key role.
But this was not always the case. Too far removed from population centres, the Chagos Islands were only settled permanently around 1783. In 1814, following Napoleon’s defeat, the islands were ceded by France to Britain. Though they were administered from officials living in the British colony of Mauritius, in practice, the long distance between the two territories and the lack of historical, cultural, and social links meant that the relationship was, for the most part, an official fiction. The plantations in the Chagos Islands, staffed by imported laborers, hummed along with little intervention from the outside world.
This changed in the 1960s, as the U.K. relinquished its empire. The U.S., which was looking for a base between the Pacific Ocean and the Mediterranean Sea, set its sights on the Chagos Islands. The two governments decided to allow the islands to be used by the U.S. as a military base. To guarantee operational security, it asked the British to assume direct control over them and to remove all its inhabitants. To do so, the islands needed to be separated from Mauritius, which was then on the cusp of becoming independent.
The Mauritian government was only too happy to sell the Chagos Islands. In the words of Sir Seewoosagur Ramgoolam, Mauritius’s first prime minister (and father of the current prime minister), the Chagos Islands were “a portion of our territory of which very few people knew … which is very far from here, and which we had never visited.” Ramgoolam agreed to sell the islands to the British, provided the right price could be obtained.
Eventually, Mauritius was given a large sum of money (much of it paid by the U.S.) and other valuable consideration to sell the Chagos Islands. In 1965, the islands were detached and became a new British territory known as the British Indian Ocean Territory. The inhabitants were expelled in the following years as the U.S. built its base. Most of them were taken to Mauritius, which many had never visited. The Mauritian government treated them as unwanted pests. They were settled in slums and, being of predominantly African ancestry, were subject to constant racial discrimination by the island’s Indian and white majority.
It was not until the 1980s that Mauritius, after electing a radical leftist government, decided to claim sovereignty over the Chagos Islands. The problem with their claim was that, for almost 20 years, the country’s government had consistently said the islands were British territory. To prove their claim, the new Mauritian government tried to prove that Mauritius’s agreement to sell the islands was obtained through blackmail. Not even one of the Mauritian ministers who participated in the talks in 1965 supported this claim, but it remains the official Mauritian position to this very day.
In the 2000s, there was a renewal of international interest in the plight of the Chagossians, many of whom heartily disliked the Mauritian state’s treatment of their people. However, Mauritius saw the PR potential. It began to claim the role of champion for the Chagossians’ rights, despite all evidence to the contrary. But the gambit was successful. In 2017, it managed to have the United Nations General Assembly ask the International Court of Justice for an “advisory opinion” about the legality of the 1965 detachment.
In 2019, ignoring overwhelming evidence proving that Mauritius sold the Chagos Islands freely and happily, the International Court of Justice provided a mistaken advisory opinion that the detachment was illegal in international law. In any case, these advisory opinions aren’t legally binding.
Mauritius’s expensive lawyers then fanned out, the advisory opinion in hand, threatening to wage lawfare on the base at Diego Garcia unless they got what they wanted. The tactic worked. In 2022, the U.K. agreed to begin negotiations on the islands. Last year, it announced that an agreement had been reached. The Chagossians were not consulted.
Under the deal, the U.K. will have to make huge payments to Mauritius every year to use Diego Garcia as a military base. Mauritius will obtain sovereignty over the entire group of islands and must be notified each time Diego Garcia is used to launch a military attack. Needless to say, all of this undermines the military utility of the Chagos Islands.
Many questions remain without answers. For example, Mauritius is in an international treaty that requires it to ban nuclear weapons from its territory. Diego Garcia is known to house nuclear weapons regularly, but no one seems willing to explain how they can be kept lawfully there if sovereignty over the islands is given to Mauritius.
BRITAIN’S CONSERVATIVE SECOND WORLD WAR
In Britain, which is afflicted with a permanent budget crisis, there is widespread incomprehension as to why the government is striking the deal. It states that international law requires it to do so if it wants to continue using Diego Garcia, but the 2019 opinion has no legal effect. So far, the most tangible consequence of Mauritius’s campaign of international legal intimidation has been that British Indian Ocean Territory stamps are no longer recognised by the Universal Postal Union. This means they cannot be used to post letters from Diego Garcia to the rest of the world. But these stamps were never used by anyone except for the occasional postcard, since the U.S. Department of War maintains its own postal service.
The reaction in the U.S. to the deal has been muted so far. One exception is Sen. John Kennedy (R-LA), who has criticised it.
“I want to see the PM do well, but he needs to put down the bong,” Kennedy told the Senate in February. This seems as fitting a description of the Chagos Islands deal as any.
Yuan Yi Zhu teaches international relations and international law at Leiden University and is a senior fellow at Policy Exchange, a leading British think tank.
