After a decades-long fight, Prime Minister Starmer in late May gave up Britain’s possession of the Chagos Islands in the Indian Ocean, while Australia keeps the Cocos (Keeling) Islands, our most distant Indian Ocean territory. The United States military has continuing use of both.

The two archipelagos differ in many ways, but they are both former British colonies and are links in the American chain of containment that stretches around China from the East China Sea to the Persian Gulf.

Britain is paying $7.1 billion to Mauritius for a 99-year lease of Diego Garcia, one of the Chagos islands, where the UK and US have shared a military base since 1971. Washington’s lease from London for the US Naval Support Facility Diego Garcia (“Camp Justice” and “Camp Thunder Cove”) expires in 2036. What the US pays Britain for the bases is not disclosed.

Meanwhile, on West Island, one of the Cocos group, Australia is paying $568 million to extend the 2441-metre runway by 150 metres, to take Boeing P-8 Poseidon surveillance planes capable of anti-submarine warfare operations, by 2026. The original cost was $184 million.

Cocos has for years provided a stopover and refuelling base for use by US B1, B2 and B-52 bombers transiting from Guam to Diego Garcia. The airport can already take Boeing 737s and smaller military aircraft. Triton unmanned aerial surveillance operations may be launched in the future from Cocos. Having no deep-water port, the Australian naval presence is confined to patrol boats, anti-people smuggling patrols, and surveillance.

Cocos is midway between Australia and Sri Lanka, close to Sumatra and the strategic Malacca, Sunda and Lombok Straits, and 960km from Christmas Island. Together, the islands make up the Australian Indian Ocean Territories, sharing an administrator appointed by the federal government. Cocos’ two atolls comprise 27 coral islands, only two of which are inhabited. Their 600 people are predominantly Sunni Muslims of Malay background whose ancestors were brought to Cocos (discovered in 1609 by a British navigator, William Keeling) in the early 19th century. Scottish merchant John Clunies-Ross put them to work on his copra plantation, paying them in Cocos rupees, redeemable only at his company store.

Britain annexed Cocos in 1857, keeping members of the Clunies-Ross dynasty in place as superintendents, answerable to the governor of Ceylon. During World War II, two airstrips were built and three bomber squadrons were based on West Island. The UK transferred possession of the colony to Australia in 1955, but almost all the land belonged to the Clunies-Ross family until 1978 when the federal government bought Cocos for $6.25 million and then forced the feudal landlords out in 1983 by refusing to use their ships.

In a referendum the following year, the Cocos population opted decisively for integration with Australia. They now vote in federal lower house elections in the electorate of Lingiari, and for the Senate in the Northern Territory. Tourism is promoted, and in 2021 Australia committed $39.1 million to create two marine parks off Cocos, intended to protect spawning blue fin tuna from poachers.

Chagos, too, has a colonial history. Initially an Indian Ocean stopover port for Portuguese (hence its name), Dutch and British sailors, the archipelago was taken over by the Dutch in 1638, who abandoned it in 1710. Plantation workers were brought from the Maldives, Seychelles, and a French possession called “Île de France”. Britain captured that from Napoleon in 1810, and renamed it Mauritius, which remained a British colony until 1968. Having initially denied that the Chagos islands were inhabited — “terra nullius” — the UK, aware of the value of the Chagos archipelago’s fishing, oil, and minerals, in 1965 excised its seven atolls with more than 60 islands from Mauritius three years before the colony became independent.

The UK said it wanted “to use certain 10 islands for defence purposes” and to “provide the land and security of tenure” by putting them under British administration. London offered £3 million as compensation to 2000 Chagossians it expelled between 1967 and 1973 from Diego Garcia to Mauritius, holding out the possibility of their return when their lands were “not needed for defence”.

Since 1971, Diego Garcia has been occupied by some 3000 UK and US military and civilian contractors, and the Chagossians have not been allowed to return. In 2010, the British Government created a “Marine Protected Area” more than twice the size of the UK, with fishing restrictions that did not apply to the US military, whose bases are accused of being a major source of pollution. That year, Mauritius launched proceedings against the MPA, which was ruled illegal in successive judgments by international courts and tribunals.

In 2018, the UK apologised for its “shameful” eviction of Chagossians, but sought bilateral discussions with Mauritius, not court decisions. In the following year, the International Court of Justice (with only the American judge dissenting) said the UK was obliged to end its administration of the Chagos islands as soon as possible. Labour leader Jeremy Corbyn condemned Prime Minister Theresa May’s defiance of the Court’s two rulings, which the same American judge opposed.

Australia distinguished itself negatively in 2019 when, in response to an UN General Assembly resolution on Mauritius which 119 member states approved, it joined Hungary, Israel, and the Maldives in supporting continued occupation of Diego Garcia by the US and UK.

The long process ended when after a discussion with President Trump, Starmer — a former human rights lawyer — eventually agreed to hand over British sovereignty of Chagos to Mauritius, and the agreement was signed on 22 May 2025. The prime minister of Mauritius described the expulsion of the Chagossians as a crime against humanity. Much of the British press called Starmer’s deal a disastrous sellout.

What John Pilger described as Stealing a Nation, in his 2004 TV documentary, continues. The Australian Government hasn’t made a statement about Diego Garcia. An early undertaking Richard Woolcott said Australia had made not to militarise Cocos Island hasn’t been mentioned.

The views expressed in this article may or may not reflect those of Pearls and Irritations.