The UK Is Coming to Its Senses About the Chagos Islands

By Daniel Vollborth, Policy Fellow 2025-2026. This article originally appeared in The National Interest.

Ahead of King Charles III’s state visit to Washington last week, the UK government quietly shelved its agreement to hand the Chagos Islands to Mauritius, while maintaining the lease on the US-UK military base on Diego Garcia Island on April 11. The agreement stemmed from a 2019 International Court of Justice opinion declaring that the United Kingdom’s possession of the Chagos Islands was contrary to international law. 

London’s decision to put the agreement on hold followed President Donald Trump’s revocation of support for the agreement after months of transatlantic debate. In this saga lies a lesson that the UK government is only now learning: the Indian Ocean is an arena of strategic competition, not a matter of obedience to advisory opinions from international courts. 

The events since the beginning of the American-Israeli attacks on Iran have forced the government of Prime Minister Keir Starmer to confront uncomfortable realities. Their lack of verbal support and initial refusal to allow the use of UK military bases were out of step with President Trump’s expectations and incurred withering criticism from the White House.

This disagreement added weight to President Trump’s reversal of his support for the Chagos deal in January, which ultimately could not proceed without the White House’s backing.

The UK government’s doctrinaire approach to international law is misaligned with an increasingly competitive global environment. This is no less true in the Indian Ocean Region (IOR), where the Chagos Islands are at the center of great power maritime and economic competition.

The prevailing worldview within the UK government is severely divorced from the attitudes of other actors in the region, such as China, India, and Mauritius. China, for example, has in recent years overseen a significant buildup in naval assets and capabilities in the Indo-Pacific. Closer to home, Beijing has made extensive efforts to colonize the Paracel and Spratly Islands and make extensive claims in the South China Sea, through which much of international trade transits.

Farther afield, China deployed its first submarine to the IOR in 2014, opened a military base in Djibouti in 2017, and has been increasing military exercises in the IOR to improve the People’s Liberation Army Navy’s (PLAN) familiarity with the region and prepare for any future conflict.

Through its Belt and Road Initiative and enormous investment in Africa and other developing states, China has seized the diplomatic initiative in the Global South, particularly with the Indian Ocean littoral states. China is the region’s leading trade partner and launched the China-Indian Ocean Region Forum to promote development and economic cooperation. Attempts by the West to engage in this sphere have encountered greater difficulty, since locals view them not as genuine overtures but as simply reactive maneuvers to counter Chinese influence.

Of these states, Mauritius is particularly close to China. They became the first African state to sign a Free Trade Agreement with them in 2021, and signed several other deals in areas such as port infrastructure and fishing. China was outspoken in its support for Mauritius in its efforts to acquire sovereignty over the Chagos Archipelago.

Mauritius has also fostered close relations with non-IOR states. Russian representatives, for example, were met in Port Louis only a few days before the signing of the handover deal, to agree to closer cooperation on fishing and “marine research.”

India and Mauritius also have close relations. Much of the Mauritian population is of Indian descent. Like China, Mauritius has seen several infrastructure projects go ahead with Indian funding and assistance. 

India and Mauritius also cooperate closely on defense. The Mauritian coast guard and police depend on Indian equipment and expertise. The Indian military recently constructed a jetty and an airstrip on Agalega Island. While not explicitly a military base, it will nonetheless serve as a useful outpost for the Indian military to monitor Chinese naval activity. This facility will join a larger network of maritime cooperation and presence in Sri Lanka, Seychelles, Madagascar, Oman, and the Maldives, as well as its own strategically located Andaman and Nicobar Islands.

India, like China, has been conducting a naval buildup, including its first successful anti-piracy operations last year. To counter the increasing influence of China, they have struck up a partnership with France and the Quadrilateral Security Dialogue (Quad), which includes the United States, Australia, and Japan. India backed Mauritius’ claim to the Chagos Islands and expected to benefit from the transfer of territory.

Russia and China both congratulated Mauritius following the International Court of Justice’s and the United Nations’ rulings on the Chagos Islands. Moscow’s and Beijing’s refusal to abide by international law in Ukraine or the South China Sea notwithstanding, both powers expect the UK to comply to its own detriment.