Speculation is rife that U.S. President Donald Trump might block an agreement between Britain and Mauritius to resolve their long-running dispute over the Chagos Archipelago in the central Indian Ocean. The United States has a stake in the Chagos group because the largest island, Diego Garcia, is home to a strategically important U.S. military base. For decades, Britain has administered the Chagos Islands with the explicit purpose of ensuring that the Pentagon can use Diego Garcia unimpeded. With London poised to return the islands to Mauritius, the United states is understandably anxious to see that its privileged military position is not lost.
The problem is that most of the world regards London’s presence in the Chagos Islands as unlawful, owing to an International Court of Justice (ICJ) advisory opinion that found Mauritius to be sovereign over the archipelago. Eager to conform with international law, London has agreed to return the islands to Mauritius on the condition that Port Louis will permit Britain to continue making Diego Garcia available to the U.S. military.
The deal is a “win-win-win-win” in the sense that it guarantees the formal decolonization of Mauritius; allows Britain to bring itself into alignment with international law; secures the future of the U.S. base on Diego Garcia; and paves the way for the indigenous people of the Chagos Islands – the Chagossians – to resettle parts of the archipelago for the first time in more than 50 years.
But critics of the deal have been vocal in their opposition. Britain’s right-wing press is adamant that Mauritius has no claim to the Chagos group (although convincing refutations of the ICJ’s ruling have been conspicuous by their absence). In both London and Washington, bad-faith actors have sought to smear Mauritius as an ally of China. This is nothing but baseless fearmongering given that Mauritius has no security relationship with China, but it has allowed critics to contrive the narrative that U.S. interests are in jeopardy.
The deal’s detractors are wrong. Wrecking the Chagos agreement would be a grave and short-sighted mistake. The truth is that the United States’ strategic interests are imperiled by the status quo, which is unsustainable and contrary to long-term U.S. interests. Only a treaty between Britain and Mauritius can provide the Pentagon with the secure, long-term access to Diego Garcia that it desires.
As Trump’s advisers will no doubt inform him, the U.S. interest in the Chagos Archipelago is singular: to retain access to Diego Garcia for military purposes. It is no concern of the United States whether Britain or Mauritius is recognized as sovereign over the Chagos group on paper. All that matters is that the base on Diego Garcia can continue to function in practice.
This is exactly what Britain’s negotiating team secured from their Mauritian counterparts. Per the agreement, the British will be allowed to exercise the powers of a sovereign authority over Diego Garcia so that London can, in turn, furnish the United States with unfettered access to the island, just as is presently the case. To be sure, Mauritius will become responsible for administering the rest of the Chagos Archipelago beyond Diego Garcia (the so-called “Outer Islands”). But these have never been touched by the United States and are unnecessary for security purposes.
In short, the Chagos agreement has been designed by Britain and Mauritius so that U.S. service personnel will hardly notice the formal handover of sovereignty. Still, it is possible that some in Trump’s circle have been swayed by the unfounded allegations that Mauritius is under the spell of China. Others might be attracted by the imagery and symbolism of flouting international law, believing that it signals strength to brush aside institutions like the ICJ and United Nations. And then there is the dubious influence of British firebrand Nigel Farage (leader of the Reform Party), who claims to have Trump’s ear and has been a staunch opponent of returning the islands to Mauritius.
If they adopt a hard-headed view of the issue, however, Trump’s team will soon discover that British administration of the Chagos group is a dead duck. For years, London has made a series of missteps that have drawn unwanted attention to the Chagos Islands, worsened the legal and political positions of Britain and the United States, and complicated the effective operation of the base on Diego Garcia.
For example, in 2015 the Permanent Court of Arbitration in The Hague found (in a binding decision) that London was obligated to consult Mauritius on important matters relating to the governance of the archipelago. In 2017, the United Nations General Assembly voted in overwhelming numbers to refer the Chagos dispute to the ICJ for an advisory opinion. And then in 2019, the ICJ issued its damning findings: that the decolonization of Mauritius was never completed, Britain’s administration of the Chagos group is unlawful, and so London is an occupying power. The U.N. General Assembly swiftly welcomed the opinion, calling upon Britain to withdraw from Chagos without delay.
These shifting legal and political sands have made a real difference. In 2022, Mauritius dispatched a delegation of diplomats, scientists, journalists, and Chagossian activists to the Chagos Islands in an effort to expose the tenuousness of Britain’s hold over the territory. It was a roaring success, with London shrinking from intercepting the Mauritian vessel and instead watching helplessly as the flag of Mauritius was hoisted over Chagos. Had British officials sought to intervene, their actions would surely have been subject to legal challenge.
The Mauritian voyage to Chagos was a turning point. It revealed that British officials are uncertain of their legal authority to detain visitors to the islands (otherwise London would have turned the Mauritian ship around) and are eager to avoid further legal embarrassment, whether in domestic or international courts. This was not the behavior of a country confident in its sovereignty – it was, on the contrary, the precise moment at which the United States could no longer count on Britain.
It was in this context that London sought talks with Mauritius over the future of the islands – a development welcomed by officials in the United States, who had come to realize that the political and legal status quo was close to crumbling. Of course, the British were pushing at an open door, given that Mauritius has long made clear its willingness to host the U.S. base on Diego Garcia. But it is still remarkable that London managed to conclude an agreement that preserves all that is good about the status quo while rectifying most of what is bad.
The United States has a strong interest in supporting the Anglo-Mauritian agreement in its current form. Trump should recognize this and give his unqualified backing to the deal. In fact, Trump might even be able to take some credit for the Chagos settlement if he moves with alacrity to encourage London and Port Louis to get a treaty done fast. He will cement ties with Britain, please Mauritius, win favor in New Delhi and other regional capitals, and – most importantly of all – place one of the Pentagon’s most important military installations beyond jeopardy.