UN Filing Accuses UK of Forced Displacement Over Diego Garcia Territory

On April 15, 2026, James Tumbridge, attorney general for the Chagossian government, filed a 12-page petition with the United Nations accusing UK Prime Minister Keir Starmer of committing crimes against humanity [1][2]. The filing centers on the UK's February 2026 removal orders targeting four Chagossians who had returned to the Chagos Archipelago — the last indigenous people physically present on their ancestral islands. "The removal of these four persons would result in the total physical erasure of the Chagossian people," Tumbridge wrote, characterizing the situation as "amounting to ethnic cleansing" [1][3].

The petition cites the Rome Statute of the International Criminal Court, invoking its definitions of "deportation or forcible transfer of population" and "other inhumane acts of a similar character intentionally causing great suffering" [2]. It arrives at a moment when every element of the Chagos dispute — sovereignty, security, colonial reparations, and the right to return — is in flux simultaneously.

The Original Sin: 1968–1973

Between 1968 and 1973, the United Kingdom systematically removed the entire indigenous population of the Chagos Archipelago to make way for a US military base on Diego Garcia, the largest island [4]. Estimates of the number displaced range from 1,151 — the figure agreed between the UK and Mauritius in a 1972 accord counting 426 families — to approximately 1,500–2,000 based on broader assessments by Human Rights Watch and other organizations [4][5].

The legal architecture of the expulsions was built in stages. In 1965, the British Indian Ocean Territory Order 1965, an Order in Council, detached the Chagos Archipelago from the colony of Mauritius just three years before Mauritian independence, creating a new crown territory under direct UK sovereignty [4]. The UK paid Mauritius £3 million for the detachment. In 1966, London signed a bilateral agreement granting Washington use of Diego Garcia for military purposes, initially for 50 years [5]. Then in 1971, the BIOT Immigration Ordinance made it unlawful for any person to enter or remain in the territory without a permit — a law later ruled unlawful by UK courts [4][10].

The displaced Chagossians were deposited in Mauritius and the Seychelles with little support. Many ended up in poverty. The community they left behind was erased: homes were demolished, pet dogs were gassed, and coconut plantations — the economic backbone of island life — were shut down [5].

Source: Wikipedia / Crawley Borough Council / HRW

Data as of Jan 1, 2024CSV

Today, the Chagossian diaspora numbers roughly 10,000 people. An estimated 4,500 live in Mauritius, approximately 3,500 in the United Kingdom (concentrated in Crawley, West Sussex), and around 1,500 in the Seychelles [16][5].

The Compensation Gap

The financial settlement the Chagossians received stands in sharp contrast to the strategic value extracted from their homeland. In 1972, the UK paid £650,000 to Mauritius for resettlement — not directly to the displaced people [5]. After street protests in Mauritius, a 1982 agreement provided £4 million to a trust fund, working out to less than £3,000 per person, with the UK admitting no liability [4][5].

In 2016, the UK government allocated £40 million over ten years for Chagossian "community projects," though community organizations have criticized the program as paternalistic and inadequate [5].

Compare these figures to the deal now on the table: under the 2025 UK-Mauritius sovereignty treaty, signed on May 22, 2025, Britain agreed to pay Mauritius approximately £3.4 billion over 99 years for the continued right to operate Diego Garcia — averaging £101 million ($135 million) per year [13][7]. The Chagossians themselves — the people actually displaced — have no direct claim on these payments. Over six decades of military use, the cumulative economic value of Diego Garcia to the US and UK defense establishments runs to many billions of dollars, while total compensation to the displaced population has not exceeded £50 million in any accounting [4][5][13].

A Deal That Collapsed

The 2025 UK-Mauritius treaty was meant to resolve the sovereignty question definitively. Under its terms, Mauritius would gain full sovereignty over the Chagos Archipelago, while the UK would retain operational control of Diego Garcia under a 99-year lease [13]. Mauritius would be free to arrange resettlement on all other islands in the archipelago — but Diego Garcia itself was excluded from any right-of-return provisions [7][8].

The deal required amending the 1966 UK-US base agreement, which meant Washington's formal consent [7][9]. That consent was withdrawn. In January 2026, President Donald Trump called the sovereignty transfer "an act of great stupidity" [11]. By February, he demanded that Britain not relinquish Diego Garcia, citing ongoing military operations against Iran [11][8]. Without the US agreeing to the necessary treaty amendments, the UK abandoned the legislation in April 2026 [8][9].

The collapse left everyone in limbo. A March 2026 ruling by Justice James Lewis of the BIOT Court affirmed that Chagossians have a right of abode on their ancestral islands — but with no sovereignty deal in place and no practical mechanism for return, the ruling remains largely symbolic [7].

Source: Multiple Sources

Data as of Apr 16, 2026CSV

The Security Case: Steelmanned

US and UK defense officials argue that Diego Garcia's military value is not merely significant but irreplaceable. The base sits at the center of the Indian Ocean, roughly equidistant from the Bab-el-Mandeb Strait and the Strait of Malacca — two of the world's most critical maritime chokepoints [17]. It is the only US military installation in the Indian Ocean [17].

The facility includes two runways long enough to accommodate B-2 and B-52 heavy bombers, a deep-water port that hosts nuclear-capable submarines, massive fuel storage depots, and secure satellite communication stations [17]. It has served as a launch point for bombing campaigns in Iraq, Afghanistan, and most recently operations related to the Iran conflict [12][17]. Intelligence operations, vessel tracking infrastructure, and signals intelligence collection all operate from the island under conditions of extreme secrecy [17].

The security argument against civilian resettlement rests on operational security. Defense officials contend that any permanent civilian presence — even on outer islands hundreds of miles from Diego Garcia — could create vectors for espionage, complicate base access, and generate legal obligations (environmental, labor, human rights) that would constrain military operations [17].

Iran's March 20, 2026 missile strike attempt underscored these concerns. Two ballistic missiles were launched at Diego Garcia from over 2,500 miles away; one failed mid-flight and the other was intercepted by a US warship [12]. The attack demonstrated that Iran possesses missiles with range far exceeding what it had previously acknowledged — putting most of Western Europe within striking distance — and it reinforced the base's centrality to power projection in the region [12].

However, independent analysts have challenged the maximalist security position. The 2025 treaty itself contemplated resettlement on outer islands while preserving the Diego Garcia base, suggesting that UK and US negotiators had already concluded that civilian presence elsewhere in the archipelago was compatible with base security [13]. Several security scholars have noted that other US bases worldwide — including Guam, Okinawa, and Bahrain — operate alongside substantial civilian populations without comparable restrictions [17].

What International Law Says

The legal case against the UK's position has been building for decades. The International Court of Justice's February 2019 advisory opinion, adopted by 13 votes to 1, found that the separation of the Chagos Archipelago from Mauritius in 1965 was unlawful, that the UK's continued administration "constitutes a wrongful act entailing the international responsibility of that State," and that Britain had an obligation to end its administration "as rapidly as possible" [6]. The UN General Assembly subsequently voted 116-6 to endorse the opinion and set a six-month deadline for withdrawal — which the UK ignored [15].

The new UN filing builds on this foundation, invoking the Rome Statute rather than relying solely on the ICJ framework [2]. Four months before Tumbridge's petition, the UN Committee on the Elimination of Racial Discrimination (CERD) had already expressed "deep concern" that the UK-Mauritius agreement would perpetuate violations of Chagossian rights, specifically warning that any arrangements must ensure meaningful Chagossian participation [2][14].

ICJ advisory opinions are not binding in the way contentious judgments are — states are free to disregard them, as the UK has done [6]. This is a structural limitation that the Chagossians share with other displaced peoples. The ICJ's 1975 advisory opinion on Western Sahara, which found no ties of territorial sovereignty between Western Sahara and Morocco, has been largely ignored by Morocco, which continues to occupy the territory and displace the Sahrawi population into Algerian refugee camps decades later [6]. In that case, as in the Chagos case, the advisory mechanism produced moral authority without enforcement power.

The Nauru case offers a partial counterpoint. Nauru brought a contentious — and therefore binding — proceeding against Australia at the ICJ over the destruction of phosphate lands during the colonial trusteeship period. Australia settled out of court in 1993, paying $107 million in compensation, rather than risk an adverse binding judgment [6]. The distinction matters: contentious proceedings carry enforcement teeth that advisory opinions lack, and the new UN filing may be an attempt to create political pressure toward a binding forum.

The UK Courts: A Revolving Door

The domestic legal history is a study in raised and dashed expectations. In November 2000, the High Court ruled in R v Secretary of State for Foreign and Commonwealth Affairs, ex parte Bancoult that the 1971 Immigration Ordinance was unlawful, and Foreign Secretary Robin Cook announced the Chagossians could return home [10][4].

That promise lasted four years. In June 2004, the government issued two Orders in Council under the Royal Prerogative — the British Indian Ocean Territory (Constitution) Order 2004 and the British Indian Ocean Territory (Immigration) Order 2004 — which permanently banned the islanders from returning, overriding the court victory without parliamentary debate [10][4].

In 2006, the High Court again ruled the Orders in Council unlawful [10]. But in October 2008, the House of Lords overturned that decision by a 3-2 majority, holding that the Royal Prerogative could be used to override the right of abode — a ruling that Lord Bingham, in a forceful dissent, called a failure to uphold fundamental rights [10].

The 2008 House of Lords decision effectively closed domestic avenues for several years. The European Court of Human Rights declined to hear the case in 2012. The March 2026 BIOT Court ruling affirming a right of abode reopened the question, but without a sovereignty framework in place, enforcement remains theoretical [7].

What Chagossians Want — and Where They Disagree

The Chagossian diaspora is not monolithic, and the internal tensions have intensified as the sovereignty deal has stalled.

Chagossian Voices, a UK-based grassroots organization, has been vocal in opposing the UK-Mauritius agreement on the grounds that Chagossians were excluded from negotiations. "We are deeply concerned that both governments have chosen to negotiate our future without us," said Frankie Bontemps, the organization's chair. "This exclusion reflects a long-standing pattern of marginalization" [18][14].

The Chagos Refugees Group (CRG), led by Olivier Bancoult, has pursued the right of return through UK courts for over two decades. Having reached a legal dead end domestically, Bancoult has expressed conditional support for Mauritian sovereignty as a vehicle for return, though he says he wants Chagossian participation in governance, not merely permission to live on the islands [14][16].

Misley Mandarin, identified as Chagossian First Minister and one of the four people who physically returned to the archipelago, has taken the most direct approach, describing the situation as "obviously ethnic cleansing" and supporting the UN filing [3].

The divisions run along geographic and generational lines. Bancoult has noted that some of his UK-based opponents are third- or fourth-generation Chagossians born in Mauritius, rather than first-generation déracinés — those who were physically uprooted from the islands [14]. The Mauritius-based community tends to prioritize practical resettlement and economic opportunity, while UK-based Chagossians, many of whom hold British citizenship and have built lives in Crawley, are more likely to emphasize legal recognition, reparations, and symbolic justice [14][16].

Across the diaspora, three demands recur: the right of return, financial reparations that reflect the actual value extracted from their homeland, and meaningful participation in decisions about the archipelago's future. Whether those demands are satisfied through Mauritian sovereignty, a revised UK arrangement, or some as-yet-unimagined mechanism remains the open question [5][18].

Where This Goes

The UN filing does not, by itself, compel action. The United Nations has acknowledged receipt of Tumbridge's submission but has not responded substantively [2]. The Rome Statute provisions invoked in the filing would need to be pursued through the International Criminal Court, which requires referral by a state party, the UN Security Council, or the ICC prosecutor — none of which has occurred [2].

Mauritius has indicated it will pursue diplomatic and legal channels through the United Nations [7]. The UK retains formal sovereignty but faces what legal scholar Tom Frost has described as "a serious and ongoing violation of international law" [7]. The US, whose consent is required for any change to the base arrangement, has signaled under the current administration that no change is forthcoming [8][11].

Meanwhile, more than 300 Chagossians have expressed interest in joining the four who returned to the islands, and Border Force officials have been intercepting supply ships attempting to resupply them [3][1]. The population that was removed from the Chagos Archipelago over half a century ago — and their descendants, now numbering ten thousand — remain caught between a colonial past that the international legal system has condemned, a sovereignty deal that great-power politics has frozen, and a homeland that their own government still bars them from entering.