British Prime Minister Keir Starmer on Oct. 3, 2024, in an agreement with Mauritius Prime Minister Pravind Jugnauth, agreed to cede sovereignty of the Chagos Archipelago—also known as the British Indian Ocean Territory, home to the strategically critical U.S. defense base at Diego Garcia—to Mauritius.
I believe the gesture weakened Britain’s global role and partnership with the United States against the expansion of power by the People’s Republic of China (PRC) into the Indian Ocean.
The move was not necessarily strategically thought through, despite United Nations (and its International Court of Justice) pressure on the UK to cede the islands to Mauritius. It was politically reminiscent of the move, in January 1968, by then UK Prime Minister Harold Wilson to withdraw UK forces from “East of Aden” in 1971.
The comparison was no doubt deliberate on Starmer’s part as a decisive move against the former Conservative government’s resumption of Britain’s global trading role after the UK withdrawal from the European Union (Brexit).
However, Mauritius is also at the center of a major U.S.–PRC discreet conflict over the control of aspects of the internet, a matter central to the global control of information. This is so sensitive that neither government nor the Five Eyes community will discuss it. However, clearly, the PRC views the cession of the Chagos to Mauritius as a significant gain for it, just as the Sept. 21, 2024, election of a Maoist president in Sri Lanka helped swing the Indian Ocean slightly more in the PRC’s favor.
Arguably, there is a better case for the UK to restore the lands of Eswatini (former Swaziland) in south-eastern Africa to that kingdom, after the UK illegally transferred Eswatini territory to South Africa and Portugal (Mozambique) in the 19th and 20th centuries when Eswatini was a British protectorate, not even a British colony.
The British Indian Ocean Territory was formed in 1965 and originally included the Indian Ocean islands of Aldabra, Desroches, and Farquhar, formerly administered by the Seychelles, and the Chagos Archipelago, formerly administered by Mauritius. The Chagos Archipelago includes the coral atoll of Diego Garcia and 57 other islands.
Diego Garcia was discovered by Portuguese explorers in the early 16th century, although there is uncertainty as to the origin of its name. Portugal’s claim to Diego Garcia lapsed and in the early 18th century the island was claimed by the French and governed from Mauritius. France retained control until after the Napoleonic Wars, when possession was ceded to the British after the capture of Mauritius. Diego Garcia’s main source of income until 1971 was from copra and coconut oil, used as fine machine lubricant and fuel to light lamps.
In 1966, the UK and the United States exchanged notes providing that the islands of the new territory would be available, for an initial period of 50 years, for the defense of either U.S. or UK interests. The UK agreed when establishing the territory that when it was no longer needed for defense purposes, it would be ceded to Mauritius. In 1980 and 1981, as part of the U.S. efforts to build up a “rapid deployment force” in the wake of the Iranian Revolution, the United States and Britain agreed to expand facilities at Diego Garcia.
There are no inhabitants of the archipelago other than several thousand British and U.S. forces stationed at Diego Garcia. There had been some 2,000 inhabitants, known as Ilois, contract workers descended from emancipated slaves, who worked the copra plantations. They were expelled to Mauritius or the Seychelles when the copra business was wound down before the construction of the base. The Ilois fought for, and in 1982 received, £4 million compensation from Britain to resettle some Ilois in Mauritius.
The U.S. Central Command used Diego Garcia extensively during the 1991 Gulf War against Iraq, and again in 1997 and 1998 during the crisis precipitated by Iraqi non-compliance with UN weapons inspectors. In 2001 and 2002, U.S. forces from Diego Garcia attacked Taliban and al-Qaida forces in Afghanistan, and later elsewhere in the region.
On May 21, 2002, an amendment to the UK’s British Overseas Territories Act, 2000, gave all people originating from Chagos full British citizenship; some 800 of them took advantage of this to settle in Britain. That group, in the UK, has now loudly protested the handing over of their islands to Mauritius.
A UK High Court ruled in 2000 that the expulsions of the island’s residents had been illegal, but maintained the special military status of Diego Garcia.
The International Court of Justice (ICJ), in September 2018, began hearing arguments from the UK and Mauritius as to who had the legal right to the islands. In 2017, Mauritius successfully petitioned the UN to seek an ICJ advisory opinion on the legality of the separation. Coming just months after the Brexit referendum, the vote to refer the matter to the ICJ was a diplomatic blow to Britain, because the UK was not supported by fellow European states as a result of Continental anger over Brexit.
The referral was highly controversial. Under Article 96 of the UN Charter, the General Assembly could request that the ICJ give an advisory opinion on “any legal question,” but the UK argued that it was inappropriate for the ICJ’s advisory opinion procedure to be used to intervene in a dispute between states that had not both consented to ICJ jurisdiction.
The ICJ, at the end of February 2019, finally rejected the UK’s claims to sovereignty over the Chagos Islands. The ICJ found that the UK had unlawfully separated the islands from the former colony of Mauritius, and that the UK should cede control “as rapidly as possible.” The Chagos Islands, like, for example, West Papua, had never made it on the 1960 UN Declaration on Decolonization list, which would have entitled it to a process of self-determination under international law.
