On February 5, US President Donald Trump announced that he had “productive” talks with British Prime Minister Keir Starmer regarding the UK’s transfer of the Chagos Archipelago, which hosts the British-American base of Diego Garcia, to Mauritius.
However, Trump warned that if “anyone threatens or endangers” local US activities, he “retain[ed] the right to militarily secure and reinforce the American presence” on the island.
Although this statement was an improvement over Trump’s earlier description of the transfer as “an act of GREAT STUPIDITY,” it reveals his administration’s inability to break from hegemony.
Assuming ratification, the May 2025 UK-Mauritius agreement, which followed a political agreement in October 2024, would return the Chagos Archipelago in exchange for a 99-year British lease of Diego Garcia, at an annual cost of approximately US$100 million.
The agreement follows a 2019 ruling by the International Court of Justice asking London to terminate its unlawful occupation.
This occupation, which began in 1965, enabled the US to gain control of Diego Garcia, the Chagos’ largest island. Its strategic relevance increased due to Britain’s withdrawal “East of Suez,” the Soviet Union’s advances in East Africa and South Asia, the rise of postcolonial Third World nationalism and growing US and allied dependence on the Middle East’s oil resources.
Since then, Diego Garcia’s central location in the Indian Ocean has enabled US power projection toward the Middle East, East Africa, South Asia and Southeast Asia. Its relative isolation also makes it valuable to the Pentagon.
Yet the Trump administration’s resistance to the UK-Mauritius transfer lacks coherence. Indeed, in February last year, Trump himself stated that he was “inclined” to accept a transfer. Likewise, US Secretary of State Marco Rubio described the May 2025 agreement as a “monumental achievement.”
Washington’s recent security concerns are misplaced. Some leaders and experts have opposed the 2025 agreement as dictated by “guilt over colonialism” and dangerous for the West’s security.
To them, Diego Garcia “could soon become China’s” due to Mauritius’ fast-rising “economic dependence” on Beijing. This would help Beijing expand its economic and military “sphere of influence” in the Indian Ocean Region, potentially in collaboration with Russia.
Mauritius’ membership in the African Nuclear-Weapon Free Zone (ANWFZ) could constrain American deployments of nuclear-capable assets while also emboldening Chinese proxies to challenge the US presence.
Finally, Beijing could also use its political influence to persuade Britain to end its payments to Mauritius.
Yet those arguments are unconvincing. The 2025 agreement is a win. It provides “legal certainty,” enabling US forces to operate in all circumstances. Washington can exploit ambiguities such as the right to “visits” and “transits” to bypass the ANWFZ – as done elsewhere before. Moreover, London secured a “veto on all development in the Chagos Archipelago.”
There is no evidence that Mauritius intends to host Chinese forces, which Beijing has not sought. Although Mauritius signed a free trade agreement with China in 2019, procures telecommunications equipment from Huawei, and has received Chinese loans, it declined to join the Belt and Road Initiative and does not count Beijing among its top export markets. The “debt-trap” thesis has been largely debunked.
India, China’s chief rival in Asia, has defense facilities in Mauritius and welcomed the 2025 agreement. More broadly, due to geographic distance, great power balancing and other structural constraints, Beijing’s rise in the Indian Ocean is inherently limited.
The Trump administration has ignored Diego Garcia’s role in some of its predecessors’ worst foreign policy failures. Many of the interventions the base enabled were strategic fiascoes.
Although the island can help deter China, it underpins an aggressive encirclement strategy that could entail cutting the sea lanes connecting Beijing to the Middle East and Africa. Some experts even suggest a local AUKUS “hub” or making Diego Garcia a “Quad (+British) base.”
Diego Garcia has also seen its fair share of human rights violations. From that perspective, although the Biden administration saw the 2024 UK-Mauritius deal as a symbol of its so-called “rules-based order,” the Chagossians, whose ethnicity and culture differ from Mauritius,’ were marginalized, denied the right to return to Diego Garcia, and saw Washington decline to offer any apology or reparations for pushing Britain to violently remove them during the Cold War.
Finally, the Trump administration appears increasingly inclined to expand this hegemonic agenda. Washington is using Diego Garcia to prepare a potential intervention against Iran. More broadly, its concerns about the island echo its new Monroe Doctrine, its $1.5 trillion 2027 defense budget goal and its efforts to extract as many concessions as possible from adversaries and allies alike.
In that regard, Trump’s attempts to link Diego Garcia to his claims over Greenland have unnecessarily antagonized the UK. However, tensions could worsen as Starmer now seeks to court China. Instead of overreaching, Washington should fully endorse the UK-Mauritius deal, repair its relationship with Britain, and exercise greater caution in assessing the strategic benefits of Diego Garcia.
Thomas P Cavanna is non-resident fellow at Defense Priorities and a collaborating academic visitor at Lehigh University. Follow him on X here.