Diego Garcia: Why a Trilateral Deal Between Mauritius, UK, and US Is Now Essential

Mauritius and the United Kingdom signed a bilateral treaty on May 22, 2025, in which London formally recognized Mauritian sovereignty over the Chagos Archipelago. According to reporting from fr.allafrica.com, the historic agreement alters the traditional two-way diplomatic tango between Port-Louis and London by exposing a structural flaw in bilateral negotiations: the absence of the United States, which operates the major military base on Diego Garcia. While the legal text addresses the archipelago’s colonial history, the strategic reality of the Indian Ocean requires direct three-way engagement involving Washington, D.C.

London, Washington, and Port-Louis Face Divergent Strategic Interests

The Chagos Archipelago spans at least 60 islands across seven atolls, located approximately 500 kilometers south of the Maldives and more than 2,000 kilometers northeast of Mauritius, as detailed by Anadolu Ajansı. Within this territory, the island of Diego Garcia hosts a vital United States military facility established in the early 1970s following the expulsion of local inhabitants between 1968 and 1973. fr.allafrica.com notes that while the United Kingdom wishes to preserve its core security relationship with Washington, D.C., and the United States seeks guaranteed continuity for its air-naval base, Mauritius aims to exercise actual sovereignty while accommodating the base’s security function. These three agendas overlap without being identical, creating a complex diplomatic triangle that existing bilateral channels fail to manage.

Jean Claude de l’Estrac Urges Trilateral Talks as Prime Minister Visits London

Mauritian Prime Minister Navin Ramgoolam traveled to London to press the British government for the ratification of the May 2025 treaty, according to lexpress.mu, while Jean Claude de l’Estrac expressed pessimism on a rapid outcome, conceding that the absence of any agreement would be terrible for the country. However, Jean Claude de l’Estrac warned that progress in London remains constrained because real authority over the pact’s fate rests in Washington, D.C. As reported by lexpress.mu, de l’Estrac pointed out that British willingness to act depends heavily on the United States, where Donald Trump has voiced strong reservations about the sovereignty transfer, having once again characterized the text as terrible during a meeting with British Prime Minister Andy Burnham on the sidelines of the UN General Assembly. De l’Estrac, who as a former Minister of Foreign Affairs chaired the 1982 Select Committee on the detachment of the Chagos and authored L’an prochain à Diego, argued that a tripartite negotiation format between Mauritius, the United Kingdom, and the United States—which he described as ce serait l’idéal—is now the ideal path forward.

Legal Uncertainty and International Law Meet Operational Constraints

Legal experts meeting at a Middle Temple Association colloquium in Mauritius examined the persistent uncertainties surrounding the archipelago’s status, as reported by Le Mauricien. In February, London denied the U.S. use of Diego Garcia to strike Iran under international law, before granting a limited authorization for defensive strikes in March, as outlined by lexpress.mu.

British Parliament Prorogation Delays Legislative Implementation

Legislative hurdles in the United Kingdom continue to stall the implementation of the sovereignty agreement. lexpress.mu reports that although the implementing bill cleared its third reading in the House of Lords in January, it became null and void when Parliament was prorogued on April 29, requiring the draft legislation to be reintroduced. Meanwhile, a British delegation comprising Royal Navy officers and Foreign Office representatives is scheduled to arrive in Mauritius to begin working sessions with the State Law Office and other ministries regarding maritime security around the Chagos, according to Le Mauricien.

French and British Colonial Administration of Chagos

Following French colonization in the 18th century, subsequent French colonists developed coprah and coconut oil production using the labor of enslaved populations, and the Treaty of Paris transferred Chagos sovereignty to the United Kingdom in 1814, with the archipelago initially administered from the Seychelles before being attached to the British colony of Mauritius in 1903, as noted in source reporting. In the 1950s, former Mauritius governor Sir Robert Scott described the Chagos as a île de rêve, echoing English captain James Horsburgh who had been shipwrecked there in 1786.

More on this story: The Telegraph Links Chagos Islands Deal to Falklands Sovereignty Claims