Chagos Archipelago under Mauritian Sovereignty:

A ‘Gain’ for the Rule-Based World Order

and a ‘Bargain’ for India


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By: Aditya Ghalsasi | Jan 12th 2024


Figure 1: Image/ CIA/ Factbook/


The Chagos archipelago comprises just over fifty islands in the middle of the Indian Ocean. The United Kingdom (U.K.) administers the islands as the British Indian Ocean Territory (BIOT), one of its fourteen overseas territories. London has exercised sovereignty over the Chagos Archipelago since 1965, when the islands were detached from the Crown Colony of Mauritius through an Order in Council authorized by the British monarch. During the same period, the archipelago was depopulated of its native inhabitants to construct a United States military facility, commonly known as the Naval Support Facility Diego Garica (NSFDG). Its existence at the expense of displaced Chagossians and a disregard for legally authentic Mauritian sovereignty claims weaken the rules-based order that encompasses the rule of law and human rights protection.

But why Diego Garcia?

Until the mid-twentieth century, the vast expanse of the Indian Ocean was essentially a British Lake. The 1956 Suez Crisis weakened the U.K.’s primacy in the region. Furthermore, the United States sought to contain the influence of the Soviet Union around the world. The U.S. Navy developed the Strategic Island Concept, which advocated the acquisition of strategically located and sparsely populated islands for military purposes. As early as February 1964, the U.K. Kingdom opened talks with the U. S. for the ‘strategic use of certain small British-owned islands in the Indian Ocean’ for defense purposes. The island of Diego Garcia attracted tangible interest from the U.S. in establishing a military communication facility, given its deep lagoon, adequate land for an airfield, and scarce native population,

The yet-to-be independent Mauritian leadership favored a long-term lease arrangement, which was unacceptable to the U.K. Consequently, the Lancaster House Agreement between the two parties guaranteed the Government of Mauritius a three-million-pound compensation. Also, it was fixed that ‘if the need for the facilities on the islands disappeared, the islands should be returned to Mauritius.’ Furthermore, in December 1966, an Exchange of Notes between the U.S. and the U. K. governments initially made the BIOT available for defense purposes for fifty years and subject to renewal for a twenty-year lease extension.

Decolonization and the Rules-Based World Order

Primarily, the detachment of the Chagos Archipelago from the Crown Colony of Mauritius violates the United Nations General Assembly (UNGA) Resolution 1514 (XV), commonly known as the ‘Decolonization Declaration.’ Under this customary law, it is illegal to dismember the colonized states before independence. Since then, London has adopted various methods that continue to hinder the resettlement of Chagossians and the return of the islands to Mauritius. Moreover, the 2010 Marine Protected Area (MPA) declaration attempts to Greenwash, meaning using environmental protection to conceal the underlying military interests in the Chagos Archipelago. The U.S. support for the UK’s continued administration of the BIOT contradicts their converging interests in maintaining a rules-based, free, and open Indo-Pacific region.

Nonetheless, the decolonization of Chagos would pave the way for a more robust rules-based world order. Firstly, Mauritius will regain sovereignty over the Chagos Archipelago under international law. A UNGA resolution was adopted on the advisory opinion of the International Court of Justice in 2019. Mauritius received resounding support from 116 United Nations (UN) member states. Secondly, the Chagossians, who have been living in exile in Mauritius, Seychelles, and the UK, will finally win their right to return to their homeland. Lastly, the US can continue to operate from the NSFDG on a firm legal basis. The Mauritian government has acknowledged the significance of the military facility to U.S. interests and has been willing to negotiate a ninety-nine-year lease agreement for Diego Garcia. Furthermore, it will enable the US and the UK to establish strategic relationships with the littoral states of the Indian Ocean.


India and the Chagos Sovereignty Dispute


A realpolitik approach has influenced India’s policies on the Chagos sovereignty dispute. Its backing of Mauritius results from its principles of anti-colonialism. However, it has tacitly acknowledged U.S. naval presence in the Indian Ocean. Indeed, this approach has been evident in India’s approach to the Chagos Sovereignty dispute. At the UNGA, India voted in favor of Mauritius to regain sovereignty over Chagos. However, in August 2016, the Indian government signed the Logistics Exchange Memorandum of Agreement (LEMOA), a modified India-focused version of the Logistics Support Agreement (LSA). Under this pact, India and the United States can access each other’s military facilities for replenishment and refueling. The NSFDG provides India s assets, such as the Boeing P-8I aircraft used for maritime surveillance and access to U.S.-controlled facilities under the LEMOA.

Furthermore, if Chagos were under Mauritian sovereignty, India could establish a unit of its Integrated Coastal Surveillance System in Diego Garcia or other outer islands of the Chagos Archipelago. India has installed eight surveillance radars on sovereign Mauritian islands. This system enables New Delhi to increase maritime cooperation with the littoral states of the Indian Ocean. Furthermore, Mauritius’ willingness to negotiate a long-term lease agreement with the U.S. complements India’s security arrangement with Washington, Indian naval vessels, and airplanes can continue accessing NSFDG for logistical purposes under the LEMOA following the decolonization of the Chagos Archipelago. Lastly, India would establish a greater strategic alignment with its partners in the Quadrilateral Security Dialogue, who either abstained or voted against Mauritius in the UNGA resolution 2019.




Doing away from the remaining vestiges of the British empire can serve the interests of regional and extra-regional powers in the Indian Ocean. The potential Chagos sovereignty dispute settlement will end the Chagossian community’s lengthy exile. The U.S. can retain effective control over NSFDG, which will be on a firm legal footing. Secondly, establishing defense cooperation with Mauritius will strengthen the U.S. presence in the Indian Ocean. As for India, it will have access to NSFDG and help forge a strong strategic partnership to address mutual concerns about China’s increasing footprint in the Indian Ocean.


Author’s Bio: Aditya Ghalsasi is a Master student at New Mexico State University, USA.