After years of intense negotiations and international pressure, Britain is on the verge of resolving its long-standing territorial dispute with Mauritius over the Chagos Archipelago, located in the central Indian Ocean. The potential deal could end decades of tension between the two countries and mark the decolonization of the islands that were unlawfully separated from Mauritius in 1965. The settlement is seen as a diplomatic victory for both nations, as well as the United States, which maintains a critical military base on Diego Garcia, the largest of the Chagos Islands.
The origins of the dispute trace back to the final years of the British Empire, when the Chagos Archipelago was controversially detached from Mauritius. In 1965, three years before Mauritius gained independence, Britain severed the islands from the colony, creating the British Indian Ocean Territory (BIOT). This move violated United Nations resolutions that called for the dismantling of colonial empires and prohibited the fragmentation of colonial territories prior to independence. Mauritius has long claimed that the islands rightfully belong to it and that Britain’s actions were illegal.
The situation escalated further when, between 1965 and 1973, Britain forcibly expelled the indigenous Chagossian population to make way for a U.S. military base on Diego Garcia. The depopulation of the islands sparked international outrage, with critics accusing the British government of committing a grave injustice against the Chagossians.
Over the years, Mauritius has consistently fought for the return of the archipelago, with its position backed by international law. In 2019, the International Court of Justice (ICJ) ruled that the separation of the Chagos Islands was unlawful and that Britain should relinquish control of the territory. The United Nations General Assembly echoed this decision, with a 116-6 vote in favor of Mauritius, further isolating Britain on the issue. As legal and diplomatic pressure mounted, it became increasingly clear that Britain could no longer ignore the calls to decolonize.
After nearly two years of negotiations, Britain and Mauritius have announced a deal that would resolve the territorial dispute. In a joint statement, both governments revealed that all but one of the Chagos Islands will be returned to Mauritius. The deal, expected to be finalized soon, has garnered support from the U.S. government, indicating that the most difficult aspects of the negotiations have been settled.
Under the agreement, Diego Garcia, the largest island in the archipelago and the site of a strategically important U.S. military base, will remain under British administration for at least 99 years. This provision ensures that the U.S. military’s access to the base remains intact, a key factor in the negotiations. The U.S. has declined to become publicly involved in the dispute, but its private stance has been consistent: the base must not be jeopardized.
In return for maintaining control over Diego Garcia, Britain will provide Mauritius with a financial support package. Although the exact sums have not been disclosed, the agreement includes an annual payment from London to Port Louis. Both countries have also agreed to collaborate on environmental conservation, maritime security, and the welfare of the Chagossian people. One of the most notable aspects of the deal is that it paves the way for the limited resettlement of Chagossians on the outer islands of the archipelago, a move that has long been opposed by the British government but supported by Mauritius.
This agreement has been hailed as a rare example of a “win-win-win-win” scenario in international relations, where all key stakeholders emerge with meaningful victories. Britain, Mauritius, the United States, and the Chagossians all stand to gain from the resolution of the dispute.
For Britain, the primary objective was to align itself with international law. The country suffered several humiliating legal defeats in recent years, including a ruling from the International Court of Justice and a rebuke from the United Nations. These decisions made it clear that Britain’s continued occupation of the Chagos Archipelago was illegal. While London could have chosen to defy international opinion, doing so would have further damaged its global reputation, particularly at a time when the country is seeking to assert itself on the world stage post-Brexit.
By reaching an agreement with Mauritius, Britain has managed to secure its strategic interests in Diego Garcia, while simultaneously bringing its actions in line with international law. This allows the UK to maintain its role as a global player in upholding international norms, a critical element of its foreign policy.
Mauritius, meanwhile, is set to achieve a significant victory in its decades-long struggle for full decolonization. The agreement acknowledges Mauritian sovereignty over the Chagos Archipelago, a key demand of the Port Louis government. While Mauritius will not have day-to-day control over Diego Garcia, it will be recognized as the sovereign power over the territory, fulfilling its legal and moral claims to the islands. Additionally, Mauritius has secured the right to pursue non-military activities on Diego Garcia, further solidifying its role in the administration of the archipelago.
The United States, for its part, is also a winner in this deal. The U.S. military has long relied on its base on Diego Garcia as a crucial hub for operations in the Indian Ocean and beyond. The bilateral agreement between Britain and Mauritius guarantees that the base will remain operational for at least 99 years, providing Washington with the legal security it has sought. The base, which was established during the Cold War, remains an essential part of U.S. defense strategy in the region, and this agreement ensures its continued existence without disruption.
Finally, the Chagossian people stand to benefit from the agreement as well. Since their forced displacement in the 1960s and 1970s, the Chagossians have fought for the right to return to their homeland. The new deal allows for limited resettlement on the outer islands, providing some Chagossians with the opportunity to reclaim a part of their heritage. While not all Chagossians are in favor of the deal—some would prefer to see Britain retain control over the entire archipelago—many of the largest Chagossian organizations have expressed satisfaction with the agreement and are now focused on working with Mauritius to develop a resettlement plan.
Despite the widespread support for the agreement, there has been some opposition, particularly within Britain. Critics have accused Prime Minister Keir Starmer’s government of “giving up” the Chagos Archipelago, arguing that the islands were a valuable asset. However, such claims are misguided. The islands were never Britain’s to give up; they were always considered part of Mauritius, and Britain’s occupation was deemed illegal by international courts. By returning the islands to Mauritius, Britain is simply rectifying a historical wrong.
Others have raised concerns about the future of the U.S. military base, suggesting that the deal could jeopardize the continued presence of American forces on Diego Garcia. However, this fear is unfounded. The agreement explicitly guarantees that the base will remain under British administration for 99 years, ensuring that U.S. military operations will continue uninterrupted.
Some critics have also speculated that Mauritius could allow China to establish a military presence in the Chagos Archipelago, a claim that has no basis in reality. Mauritius has shown no interest in hosting a Chinese base, and the agreement with Britain makes it clear that Diego Garcia will remain a U.S. and British military installation. Such accusations are more reflective of geopolitical anxieties than of any genuine threat.
While the agreement between Britain and Mauritius marks a significant milestone in resolving the Chagos dispute, there are still steps to be taken. The final treaty between the two nations has yet to be ratified, and the details of the bilateral arrangement will need to be carefully scrutinized. However, with both governments, as well as the U.S. administration, publicly endorsing the deal, it seems likely that the treaty will be finalized without major obstacles.
For Britain, this agreement represents the end of one of the last vestiges of its colonial empire. The Chagos Archipelago dispute has been a source of shame for the UK, and its resolution will allow Britain to turn the page on a difficult chapter in its history. For Mauritius, it marks the culmination of a long-fought battle for sovereignty and justice. And for the United States, the agreement provides long-term security for one of its most important military bases.
