(4 Minutes Read)
The UK has officially agreed to return sovereignty of the Chagos Islands (excluding Diego Garcia) to Mauritius, ending a decades-long colonial dispute, though the military base on Diego Garcia remains under UK-US control. While the deal includes financial compensation and resettlement rights for displaced Chagossians (excluding Diego Garcia), it has sparked criticism for denying full indigenous return. Concerns persist over possible nuclear weapon storage on Diego Garcia, which challenges Mauritius’s obligations under the African Nuclear Weapons Free Zone (Pelindaba Treaty). The agreement reflects a broader geopolitical struggle in the Indian Ocean, balancing decolonization, regional security, and global power rivalries.
Last week, the Chagos Islands—a remote archipelago in the Indian Ocean—captured global attention as a long-standing dispute between the United Kingdom and Mauritius came to a historic conclusion. On May 22, UK Prime Minister Keir Starmer officially signed an agreement transferring sovereignty of the Chagos Islands back to Mauritius, marking the end of a protracted legal and diplomatic battle.
Mauritius, a former British colony, became independent in 1968. However, Britain refused to relinquish the Chagos Islands, declaring them the British Indian Ocean Territory (BIOT). Later, the UK signed a 99-year lease with the U.S. in 1970, allowing construction of a military base on Diego Garcia, the largest island in the Chagos archipelago. The indigenous populations of the islands were subsequently expelled from their homeland, in a blatant violation of human rights.
For decades, Mauritius has been pushing hard to reclaim the Chago Islands. The United Nations and the International Court of Justice also upheld the legitimate claim of Mauritius over the Island. In 2019, the International Court of Justice ruled that the UK had unlawfully retained the Chagos Islands despite releasing Mauritius from its colonial rule. However, the UK resisted, citing security reasons.
Under mounting international and local pressure, a landmark agreement was finally reached between the UK and Mauritius on May 22nd. The UK-US alliance exempted Diego Garcia from the deal, retaining control over the strategic military base. The UK has agreed to give Mauritius a financial compensation of USD 136 million annually until the lease is in operation. The deal also promises joint efforts in environmental protection, maritime security, and combating illegal activities in the region.
It was also agreed to allow the indigenous population of the other almost 50 islands in the Chagos archipelago to return to their homelands. The UK has also committed a trust fund of USD 54 million to facilitate their relocation. However, no resettlement will be allowed in the case of Diego Garcia, denying the Chagossians their right to return to their ancestral land. This has created severe resentment.
Though hailed as a significant triumph in decolonisation, the Chagos deal has raised many complex questions.
Is it the possible presence of nuclear weapons in the military base in Diego Garcia that the UK and the US want to continue to retain the island?
It is well-known that since 1986, after it became fully operational, Diego Garcia base has played a critical role in U.S. operations from Vietnam to Iraq and Afghanistan. Equipped to support nuclear submarines, aircraft carriers, and large military aircraft, the base serves as a key hub for U.S. intelligence-gathering. More recently, it has played a central role in military operations, in US-UK strikes on Houthi targets in Yemen (2024–2025), and humanitarian missions to Gaza.
These military exercises suggest that the US uses the Diego Garcia military base to store or transport nuclear warheads or deploy nuclear-equipped aircraft. Political observers are also worried about the absence of any Nuclear-Weapon-Free Zone (NWFZ) treaty between the US and the region. While the US has signed and ratified treaties with Latin America and the Caribbean as a Nuclear-Weapon-Free Zone, no such treaty exists in the case of Africa.
At the same time, Mauritius is signatory to the Treaty of Pelindaba, which creates an African Nuclear Weapons Free Zone (ANWFZ). As a signatory of Pelindaba treaty, Mauritius is obligated to uphold the region’s nuclear-free status.
Under the new deal, Diego Garcia military base is in the sovereign territory of Mauritius; The question is, will Mauritius demand compliance and ensure that no NWs will be located or pass through Diego Garcia to maintain the sanctity of the Pelindaba Treaty? If not, it will set a dangerous precedent that can undermine the African NWFZ. If Mauritius fails to achieve adherence to ANWFZ, other member nations can call for the expulsion of Mauritius from the Treaty.
Maritime piracy and terrorism are major challenges in this region. For the US and the UK, the military base in Diego Garcia ensures security for their shipping lines that cross the Indian Ocean to transit energy and goods between Europe, Asia, Africa, and the Middle East. Diego Garcia is also critical in the geostrategic scheme of the US and the UK to counter China’s growing clout in the Indian Ocean Region.
It remains to be seen how this complex and multifaceted deal will unfold. The long-term success of the deal depends on how effectively it balances historical grievances, strategic interests, and regional security concerns. The Indo-Pacific islands are increasingly becoming strategically important to major global powers. However, the challenge for these island nations lies in how they can effectively navigate complex geopolitical dynamics and safeguard their interests.
