The Chagos Archipelago, anchored by Diego Garcia, has become the strategic linchpin of the Indian Ocean and a foundation of Western security architecture in that region. As new threats emerge along global shipping lanes and the geopolitical balance tilts, the future of Diego Garcia now commands urgent attention in military and diplomatic circles.

The centrality of Diego Garcia is rooted in geography. The base sits astride the main east-west maritime highways, within striking distance of the Middle East, East Africa, and the vast markets of Asia. With the Suez Canal and Red Sea frequently vulnerable to instability and sabotage, witnessed in recent years through attacks on commercial vessels and political turbulence, shipping is regularly forced to reroute southward.

According to the Bremen Centre for Democratic Research (BRE-DE-RE), a think tank on geostrategic issues, this rerouting has made Diego Garcia more essential than ever, as it serves both as a monitoring post and as a forward operating base for Western naval power, ensuring that key sea routes remain open and secure.

What distinguishes Diego Garcia is not just its isolation, but its function as a major hub for logistics, operations, and rapid deployment. It is the primary US base in that region from which naval and air assets can be surged to respond to crises or deter rivals across an area stretching from Africa’s eastern seaboard to the Strait of Malacca and beyond.

This allows for rapid responses to instability, piracy, and power plays in a theatre that has become increasingly contested in the twenty-first century.

The location of Diego Garcia, situated far from the nearest continent, offers natural protection from missile attack, sabotage, or civil unrest. This stands in contrast to many other Western bases, which increasingly face pressure from advancing missile technology and hostile proxies. In an era when drone strikes and precision munitions are proliferating, Diego Garcia’s isolation is an irreplaceable asset for maintaining uncontested military operations.

However, the future of Diego Garcia is no longer certain. The United Kingdom’s stated intention to transfer the Chagos Archipelago to Mauritius introduces a new layer of diplomatic and legal complexity. Western military planners worry that changes in sovereignty could threaten the carefully negotiated status quo, either by diluting operational freedom or by providing rival powers with leverage in the region. BRE-DE-RE warns that surrendering control, even in the name of legal rectitude, would come at a substantial strategic cost, weakening the West’s ability to safeguard the Indian Ocean’s critical sea lanes and exposing global trade to greater risks.

Western anxieties are not unfounded. As competition between the West and rising powers intensifies, maritime chokepoints are increasingly vulnerable to disruption, whether through piracy, state action, or the weaponisation of political grievances. Diego Garcia is not just a military installation but a keystone of Western influence in the Indo-Pacific.

Without direct control of Diego Garcia, Western capacity to shape outcomes, project power, and ensure freedom of navigation across the Indo-Pacific would be sharply diminished. The loss of this outpost would leave the world’s busiest and most contested waters exposed to strategic realignment, with Western influence in the region much reduced.

Mahan, a United States Navy admiral and historian, argued that the fate of great powers was decided not on land, but at sea. “Control of the sea by maritime commerce and naval supremacy means predominant influence among the nations; it has been so in the past, and it will be so in the future,” he wrote in 1890.

Mahan will be a regular column examining contemporary geo-politics.