America is conspiring in the Chinese annexation of the Indian Ocean

US complacency over the future of Diego Garcia will be exploited by a Beijing bent on domination

On October 3 2024, the UK Government announced that it had concluded an agreement to hand over full sovereignty of the Chagos Archipelago, a group of islands in the southern Indian Ocean, to the government of Mauritius, with the exception of Diego Garcia, over which the UK will retain control for an initial period of 99 years.
Since the 1970s, the US has operated a strategic military facility on Diego Garcia which it leases from the UK. While the base will remain in place after the UK and Mauritius sign a treaty on the planned handover of sovereignty, this development marks a potentially significant shift in the political and security context of a crucial US strategic military node in the Indian Ocean. In effect, the US is now sub-leasing its Diego Garcia facility not from the UK as the sovereign power, but as a Mauritian tenant.  
British sovereignty over the Chagos islands has been disputed by Mauritius, and former Chagos islanders who were evicted when the base was built. In both 2019 and 2021, the International Court of Justice gave formal support to the Mauritian claim. The UK and US governments have both stated that the new arrangement puts this argument to rest and sets the status of the base on an undisputed legal footing for the first time. The UK Prime Minister, Sir Keir Starmer, had told his Mauritian opposite number that this was important to “protect the continued operation of the UK/US military base”. Mauritius, with UK financial support, will now begin a program to resettle Chagossians in the islands – except on Diego Garcia.
At face value, this process seems straightforward; a civilised, managed exercise in de-colonisation that maintains the integrity of an important Western military facility. There are, however, many – in both the US and UK – who strongly disagree.
The People’s Republic of China has ambitions to replace the US as the dominant world power. The ruling Chinese Communist Party directs all its policies to achieving this end, from cyber and human espionage to political and economic coercion, manipulation of international institutions and rapid military modernisation and expansionism.
It regards the Pacific and Indian oceans as a connected strategic space in which China aims to exercise ever-greater military control. To this end, it is increasing its capacity to operate across the Indian Ocean. So far its first naval base is in Djibouti, ostensibly for anti-piracy operations. But China can already make military use of ports it has developed in client states including Cambodia, Bangladesh, Sri Lanka, Myanmar and Pakistan.
In this process, the Indian Ocean has become increasingly insecure. As tension between China and the West increases over Taiwan, it is emerging as a hotbed for China’s rivalry with the US. As in the South and East China seas and even further afield in the Pacific, so the US must regard the Indian Ocean as contested space.
Currently, the most significant guarantor of maritime control and security in the Indian Ocean is the Indian navy. But it is not keeping up with China’s rapid increase in naval capabilities, especially in the field of submarine warfare. China has sold submarines to Pakistan, Bangladesh and Burma and could use their facilities to service its own. Without robust co-operative defence policies linking the US and its key allies, including India and Australia, fundamental Western interests in the Indian Ocean will be exposed to increasing threats.  
Although the White House welcomed the new deal, other senior US and UK politicians, officials and advisors expressed grave concerns about the potential erosion of Diego Garcia’s strategic resilience. Diego Garcia supported US operations in Iraq, Kuwait and Afghanistan. It is a vital centre for monitoring military developments in space. Its role in supporting underwater operations could be crucial in future conflict.
This is no longer a time of peaceful globalisation and growth. China, Russia and their proxies are working to overturn the US-led status quo. Xi Jinping ceaselessly talks of building “combat readiness” to create “changes unseen in a century” that will “introduce a new era’. Perceived weakening of a vital Western position in strategic maritime space is a gift to our enemies and a worry for our allies. As the advisor to a former UK defence minister has said, “of course this deal benefits China”.
Though Mauritius has historic ties to India, in early 2021 it was the first African nation to implement a free trade agreement with China, since when bilateral trade has increased rapidly. Thirty years ago, China was already buying so much shark’s fin caught illegally in Chagossian waters that their once-pristine local coral ecosystem was severely damaged. Despite Mauritian assurances, it may not be long before other “fishing vessels” are able to patrol the seas near Diego Garcia, trawling for a far more dangerous harvest of US cyber intelligence.