Some treaties are signed with fanfare and forgotten with relief. Others, like the 1996 Pelindaba Treaty—Africa’s nuclear-weapon-free zone agreement—lurk quietly in the archives until someone rewrites the map. Sir Keir Starmer’s decision to hand the Chagos Archipelago over to Mauritius has done just that. It has revived a document most American officials couldn’t identify in a quiz, and it has triggered alarm in the one place where maps and treaties tend to matter: Washington.
Until now, the UK’s stewardship of the Chagos Islands offered legal and geopolitical clarity. The U.S. Navy could operate its base at Diego Garcia, the Pentagon’s unsinkable aircraft carrier in the Indian Ocean, without the legal baggage of nuclear entanglements. But the moment the UK cedes sovereignty to Mauritius, it triggers the Pelindaba clause prohibiting the stationing of nuclear weapons in territories of signatory states. Mauritius is a signatory. The U.S. is not. Cue the lawyers, the Chinese, and a legislative storm on Capitol Hill.
The Biden-era State Department might have let it slide, but this is President Trump’s Washington now. And Trump’s Washington, unlike the last one, smells a trap. The House Appropriations Committee is already sharpening its knives. Language has appeared in the latest State Department funding bill demanding assurances that Diego Garcia will remain fully operable and exempt from Pelindaba constraints. Senator Jim Risch (R-Idaho) has called the deal a “strategic gift to Beijing.” Secretary Rubio is watching with undisguised irritation. And deep inside the Beltway, analysts are whispering what ought to be shouted: the UK is risking U.S. strategic interests to score post-colonial virtue points.
Starmer, ever eager to impress at the UN cocktail circuit, seems blissfully unaware that the very treaty Mauritius is party to was written in the language of nuclear disarmament activism. Pelindaba, named after South Africa’s old weapons site, wasn’t a strategic pact, it was a gesture of post-apartheid moral hygiene. Now, thanks to London’s eagerness to “decolonize,” it has become a potential tool for adversaries of the U.S. security umbrella.
The administration might claim it can negotiate side agreements with Port Louis. But Mauritius isn’t just another Indian Ocean state. It’s a voting bloc darling at the UN, backed by China on nearly every major multilateral file. It has no navy, no leverage, and no particular incentive to resist Beijing’s courtship. Giving Port Louis legal sovereignty over Diego Garcia hands China not just a propaganda win, but a potential lever over U.S. nuclear deployment strategy in the Indian Ocean basin.
Even if Mauritius pledges to exempt Diego Garcia from Pelindaba’s terms, the legal ambiguity alone is a poison pill. Future Mauritian governments, or their lawyers, could claim violations. China could sponsor complaints at the UN. And American war planners, already dealing with fractured basing rights from Djibouti to Darwin, would find themselves relying on the goodwill of a small island nation that’s never hosted a naval exercise.
Mauritius is not the threat. The framework Mauritius is joining is. The Pelindaba Treaty was not designed for strategic realism. It was designed for Geneva NGOs and African National Congress speechwriters. The minute Washington allows Diego Garcia to come under its jurisdiction, the strategic utility of the entire base may be degraded, or worse, subjected to decades of legal attrition.
There’s a reason the United States doesn’t put its aircraft carriers in Belgian harbors. It’s not just about geography, it’s about jurisdiction. You don’t park nuclear-capable assets under treaties written by states that fantasise about a denuclearized world order. If Trump’s National Security Council is paying attention—and it seems they are—then Starmer’s surrender can still be stopped.
The Chagos issue isn’t about decolonization. It’s about deterrence. And if Britain wants to moralise itself into irrelevance, fine. But the United States shouldn’t be dragged into the Pelindaba trap just to help Keir Starmer polish his conscience.
Bepi Pezzulli is a Solicitor of the Senior Courts of England and Wales and a foreign policy scholar. He is a member of Advance UK’s College and a councillor of the Great British PAC. He tweets at @bepipezzulli.
Image from Grok.