On May 22, 2025, the agreement between the UK and Mauritius concerning the Chagos Archipelago, including Diego Garcia, was concluded. Both parties agreed that nothing would compromise the continued, secure, and effective functioning of the joint UK–US military base on Diego Garcia and committed to cooperating to ensure its uninterrupted operation.
Despite decades of pressure arising from decolonization efforts, the right of the Chagossian people to return to their ancestral lands, Mauritius’s demand for sovereignty, and sustained engagement by the international community and multilateral institutions, the special status of Diego Garcia remains unchanged. Even after sovereignty over the Chagos Islands was acknowledged and welcomed by the UK and all major powers, Diego Garcia remains militarized, and the Chagossians’ dream of returning to their ancestral lands on this island remains unfulfilled.
The agreement is yet to be ratified. However, the central question remains: why was Diego Garcia’s special status not negotiated? Understanding this requires examining interlocking factors that continue to place strategic necessity above sovereignty, justice, and decolonization.
The Centrality of Diego Garcia in Washington’s Indian Ocean Strategy
Diego Garcia has a special status in the United States’ grand strategy due to its vital location. It is situated along major international trade routes between Asia and Africa in the Indian Ocean. Over the years, multiple air operations have been undertaken from this base in wars such as the Gulf War and the wars in Iraq and Afghanistan, as well as, most recently, air strikes on Houthi rebels in Yemen. This military base has provided the United States with strategic depth and tactical command across the Indian Ocean. It offers logistics, surveillance, and intelligence support for operations against state and non-state actors. This base has evolved into one of Washington’s most important overseas installations.
The base has a military infrastructure capable of deterring a wide range of threats and aggression and of defending Washington’s interests in the Indian Ocean, especially the western Indian Ocean region and the Arabian Sea. It hosts a full range of facilities, including a deep-water port capable of berthing aircraft carriers, a long runway that enables deep-strike operations, advanced satellite communication facilities, satellite-tracking infrastructure, and a Navy Support Facility, and is home to 16 separate commands.
This military base has been constructed and upgraded over the years. The United States has heavily invested in building and maintaining this base because it supports its national interests in a region far from its territory. Diego Garcia is thus a key geostrategic and logistical support base for the United States’ interests, missions, and operations in the Indian Ocean region, with full military capabilities, making it difficult to replicate elsewhere without substantial financial and political cost.
The UK’s Only Base in an Indian Ocean Island State
The UK government has acknowledged Diego Garcia as absolutely vital to its strategic calculus in the Indian Ocean region. This military base represents the UK’s last remaining foothold in an Indian Ocean island state, making it a strategic asset that the UK cannot afford to lose. The base has played a key role in countering a wide range of threats, including piracy, safeguarding maritime trade, deterring hostile countries and terrorist groups, and defending the interests of the UK and its allies in this region for over 50 years.
Since the 1970s, policing and customs have been carried out by the UK through a civil administration known as Naval Party 1002, composed of personnel from the Royal Navy and Royal Marines. Even though the United States has conducted military activities on Diego Garcia, the UK has administered the island. The UK government has negotiated the deal with Mauritius and agreed to pay an average annual cost of about £101 million for a 99-year lease, in recognition of the base’s enduring strategic value. At present, the UK views continued access to Diego Garcia as essential to protecting its national interests and maintaining its relevance within the evolving security architecture of the Indian Ocean region.
Growing Presence of China in the Indian Ocean
China is making continuous and systematic efforts to establish a base and logistics network in the region. It has significantly grown its presence in the last three decades. It has invested in or built 17 ports across the Indian Ocean region, including Mombasa in Kenya, the deep-water port at Gwadar in Pakistan, the Doraleh Multipurpose Port in Djibouti, Hambantota Port in Sri Lanka, and the Darwin Port in Australia. It has provided undersea cables to Indian Ocean island states such as Seychelles, the Comoros, the Maldives, and Sri Lanka. China has established a firm foothold across the Indian Ocean region by opening embassies in every Indian Ocean country and is one of the most important economic partners for nearly all of them.
This growing presence in this region is very much part of Beijing’s maritime strategy, as it imports 80 percent of its oil and LNG through the Indian Ocean. The essence of this mission is protecting the sea lines of communication connecting East Asia to the western Indian Ocean and East Africa. With the growing presence of China, the Diego Garcia base has become even more important strategically for the UK and its allies, as it serves as a stable and uncontested operating base that protects their interests in an increasingly competitive maritime environment.
Diego Garcia occupies a central place in Western power projection in the Indian Ocean. At a time of rising regional and global tensions, major powers are unwilling to accept strategic disadvantage. The settlement makes clear that Mauritius gained formal sovereignty, but this did not translate into the demilitarization of Diego Garcia. The settlement echoes the conditions under which the Chagos Islands were detached from Mauritius in 1965 as a condition imposed ahead of independence. For years, Diego Garcia has provided a strategic advantage in the region, giving the UK and the US leverage to counter threats.
This military base not only has a strategic location but has also been built from scratch over the years with one goal: protecting the interests of Western powers and their allies. Even as international law and multilateral institutions continue to exert pressure, the footprint of freedom remains an irreplaceable strategic asset for Western powers and their allies, which they cannot afford to negotiate away. However, this footprint of freedom comes at the expense of Chagossians’ dreams of returning to their ancestral land, Diego Garcia.
