Keir Starmer is set to encourage Donald Trump to acknowledge that a US dismissal of Mauritius’s legal claim to the Chagos Islands, which includes the strategically important US military base at Diego Garcia, could escalate tensions akin to those in the South China Sea. Starmer is scheduled to meet Trump next Friday primarily to discuss the future of Ukraine, but will also address a UK initiative for Gaza’s reconstruction under international protection, allowing Palestinians to remain in the Gaza Strip. This proposal aligns with, yet differs from, discussions among Arab foreign ministers in Riyadh, which emphasize a strong international component and aim to prevent Hamas from governing Gaza.
Starmer’s team plans to bring up the Chagos agreement, in which the UK compensates the Mauritius government for a 99-year lease on the islands, a group of atolls in the Indian Ocean often referred to as Britain’s last African colony. They will stress that the agreement was based on security considerations rather than a commitment to international law, a principle that does not resonate with the Trump administration.
The UK government has faced backlash over the decision to transfer control of the islands to Mauritius, despite the fact that the UK will retain control for nearly a century under the agreement. An interim deal was reached last year, building on efforts initiated by the Conservative government, but following the re-election of Navin Ramgoolam as Mauritian prime minister in November, he sought to renegotiate the terms.
A continuous stream of UK Conservatives has been attempting to persuade the Trump administration to reject the deal, causing embarrassment for the Starmer government. The interim agreement negotiated between the Labour government and the previous Mauritian administration last year received backing from the outgoing Biden administration.
The UK acknowledges that the new Trump administration has the authority to reassess the deal’s implications for the Diego Garcia base, but hopes that Pentagon officials who supported the agreement under Biden will continue to advocate for it to the new defense secretary, Peter Hegseth. The UK anticipates a US decision in weeks rather than months, and if Trump were to veto the agreement, the UK would likely have to withdraw from the draft agreement with Mauritius.
The UK contends that although a 2019 advisory opinion from the International Court of Justice stated that the islands belong to Mauritius, it could eventually become binding, impacting maritime law and the provision of services on the islands by third parties. The UK argues that finalizing a deal now, which it believes will endure for the next century, is a preferable way to navigate the geopolitical complexities surrounding the US lease on the base. If no agreement is reached, the UK warns that China could exploit the islands’ disputed status to establish listening posts or bases on the outer islands, leading to a contested security environment in the Indian Ocean.