When Decolonization Meets Human Rights: CERD’s 2025 Decision on the Chagos Agreement

Debates on the Chagos Archipelago have long been framed through questions of territorial sovereignty and decolonization, largely as a bilateral matter between the UK and Mauritius. Human rights dimensions have not been absent, as Chagossian claims have appeared in domestic courts, before the European Court of Human Rights, and in several UN mechanisms, but they have not always been central to the diplomatic processes surrounding negotiations. Against this backdrop, the Committee on the Elimination of Racial Discrimination’s 2 December 2025 decision (see press release), adopted under its Early Warning and Urgent Action Procedure, adds  a distinct human rights interpretative layer at a crucial moment: the 22 May UK–Mauritius Agreement (the UK Mauritius Agreement) still awaits domestic ratification and Chagossian organizations in Mauritius, the UK and Seychelles have expressed opposition to the treaty. Chaggosians argue that they were not consulted and that its terms would perpetuate, rather than remedy, the long-standing denial of their right to return.

This post considers the legal and political significance of CERD’s decision, particularly in relation to the 2019 ICJ Advisory Opinion, General Assembly resolution 73/295 and the UK–Mauritius Agreement, an instrument the two States have portrayed as the outcome of extended diplomatic negotiations and as consistent with the Advisory Opinion and the subsequent General Assembly resolution.

Decolonization framework and the 22 May Agreement: A treaty concluded in absence of those it affects

In 2019, the International Court of Justice issued its Advisory Opinion on the legal consequences of the separation of the Chagos Archipelago from Mauritius finding that (a) the decolonization of Mauritius had not been lawfully completed in 1965 when the Chagos Archipelago was separated; (b) the United Kingdom was under an obligation to bring its administration of the Archipelago to an end “as rapidly as possible”; and (c) all UN Member States were obliged to cooperate with the United Nations in order to complete the decolonization of Mauritius.

Paragraph 181 of the Advisory Opinion states that

as regards the resettlement on the Chagos Archipelago of Mauritian nationals, including those of Chagossian origin, this is an issue relating to the protection of the human rights of those concerned, which should be addressed by the General Assembly during the completion of the decolonization of Mauritius.

The General Assembly subsequently adopted Resolution 73/295, which welcomed the Advisory Opinion, affirmed that “the resettlement of Mauritian nationals, including those of Chagossian origin, must be addressed as a matter of urgency during the completion of the decolonization process”, and urged the UK to cooperate with Mauritius in “facilitating the resettlement of Mauritian nationals, including those of Chagossian origin, in the Chagos Archipelago, and to pose no impediment or obstacle to such resettlement.”

Although neither the Advisory Opinion nor the resolution is legally binding, both have carried significant normative and political weight and the negotiating States describe the UK-Mauritius Agreement as emerging from the diplomatic engagement that followed the 2019 Advisory Opinion and as reflecting the alignment they consider necessary with the Opinion and the ensuing General Assembly resolution.

While the UK-Mauritius Agreement provides for the transfer of sovereignty to Mauritius, establishes mechanisms for bilateral cooperation, and outlines a framework for a future relationship between the two States, it has nonetheless been subject to criticism from Chagossian communities and to international scrutiny. In June 2025, several UN Special Procedures mandate holders expressed concerns regarding the absence of consultation, the continued prohibition of return to Diego Garcia, and the broader implications of the treaty for the rights of displaced Chagossians (see joint press release).

These concerns relate in particular to Article 6, which prohibits any return to Diego Garcia, the centre of social, cultural, and spiritual life prior to the expulsions, while permitting the continued operation of the US military base for 99 years, with the possibility of a 40-year extension. Resettlement on other islands is left to the sole discretion of Mauritius, with no further safeguards. The Agreement also establishes a trust fund, but without specifying guarantees for Chagossian participation, oversight, or access to benefits. A further, and significant concerning feature of the Agreement is the absence of direct and inclusive consultation and participation by Chagossian communities in the negotiation process.

The CERD decision: A timely and consequential intervention impossible to ignore

CERD’s Decision of December 2025 is exceptional for both its timing and its form. Acting under the Early Warning and Urgent Action Procedure (see guidelines), the Committee may issue statements, letters, or more rarely, decisions. Decisions are reserved for situations where CERD considers that discriminatory patterns risk becoming entrenched or irreversible if left unaddressed. Not legally binding, these decisions nevertheless constitute the Committee’s authoritative interpretation of State obligations under ICERD and carry significant normative and political weight.

That CERD chose to issue a decision while domestic ratification of the UK-Mauritius Agreement was imminent is therefore notable. The Committee signaled that the potential consequences of entry into force were not abstract: once ratified, the exclusion of Chagossians from Diego Garcia, and from any process capable of reconsidering that exclusion, would become structurally entrenched for generations. Preventing such crystallisation is precisely the purpose of the Early Warning Procedure mechanism, and CERD deployed it as designed.

What the decision accomplishes is threefold.

First, CERD identifies the Chagossians as a distinct ethnocultural group whose historical displacement continues to generate discriminatory effects. It situates the UK-Mauritius Agreement not as a neutral fresh start but as the latest step in a continuum that began with the forced removals of the late 1960s and extends through decades of marginalization in both the UK and Mauritius. In doing so, CERD underscores that the human consequences of displacement remain relevant to the assessment of contemporary treaty arrangements.

Second, CERD concludes that the Agreement is “inconsistent” with UN General Assembly Resolution 73/295, particularly on the request to facilitate the resettlement of Chagossian people in the Chagos Archipelago without imposing any “impediment or obstacle to such a resettlement”. This is not a peripheral remark but a substantive assessment of how the treaty aligns with the parameters the General Assembly associated with the completion of decolonization. Interestingly, Resolution 73/295 does not expressly mention resettlement on Diego Garcia and its language leaves open the question of how resettlement across the different islands should be approached. It is also true that the UK-Mauritius Agreement prohibits resettlement only on Diego Garcia, while leaving potential resettlement on other islands to the discretion of Mauritius (yet, with no guarantees). CERD interprets the resolution’s general reference to resettlement through the lens of its own mandate on non-discrimination, cultural identity, and equal enjoyment of rights. From this vantage point, a long-term categorical prohibition on return to Diego Garcia raises concerns about whether the treaty is compatible with the objectives and spirit of Resolution 73/295. In emphasizing the specific implications of exclusion from Diego Garcia, rather than treating all islands as interchangeable, the Committee highlights aspects of cultural and ancestral connection that the General Assembly text did not explicitly address. In this respect, CERD’s analysis goes beyond the resolution’s literal terms by articulating the human rights implications embedded within the resettlement question.

Third, CERD calls upon the UK and Mauritius to suspend ratification of the Agreement. Such a recommendation is institutionally remarkable. It represents a UN treaty body requiring two sovereign States to halt a bilateral treaty process on the basis of human rights concerns.

Taken together, these elements render the 2025 decision a timely and analytically precise intervention whose political implications are significant enough that it will be challenging for the UK and Mauritius to ignore as the ratification process unfolds.

The outstanding issue: A duty to consult or a duty to enable resettlement?

CERD’s decision does not resolve a central tension raised by the UK-Mauritius Agreement: whether the core legal concern lies in the absence of meaningful consultation with Chagossian communities or in the terms of resettlement offered under the treaty. Both dimensions appear in the Committee’s reasoning, but the relative weight of each remains open to interpretation. From a procedural perspective, the lack of consultation is difficult to reconcile with principles of participation, non-discrimination, and equality, particularly given the historical context in which the Chagossian people were displaced. As the administering power, the UK bears a specific responsibility to ensure that any remedial process meaningfully engages those it previously removed, rather than relying on minimal or perfunctory exercises. The recent survey launched by the House of Lords, does not satisfy this requirement: occurring too late in the process, the initiative also lacks the structure, safeguards, and inclusiveness necessary for a process intended to elicit the views of a displaced community with diverse experiences and aspirations.

The substantive question of resettlement, including whether return to Diego Garcia must be enabled, therefore arises only after the procedural question is addressed. It is for Chagossian communities, all of them, not for the UK and Mauritius alone, to articulate whether they seek permanent resettlement, limited forms of access, opportunities to visit cultural and ancestral sites, or other modalities of connection to Diego Garcia and other islands. CERD’s decision highlights that a treaty regulating the future of the Archipelago cannot be fully evaluated without such consultation and participation.

A remarkable decision: What comes next?

CERD’s decision does not resolve the many legal and political questions surrounding the future of the Chagos Archipelago and its people. Nor does it purport to do so. It does something more important: it prevents its premature closure and underscores that decolonization cannot be completed through a treaty that excludes those most affected. A bilateral settlement that prohibits return, limits consultation, and effectively freezes the Chagossian presence on their homeland for another century reflects a misunderstanding of the legal architecture of decolonization.

For decades, the geopolitical centrality of Diego Garcia overshadowed the human consequences of displacement—the UK-Mauritius Agreement was framed as the long-awaited settlement of the Chagos dispute. But CERD has pierced that convenient fiction and has reminded us that such closure is impossible without the participation and consent of the Chagossian people.

The decision also signals that UN human rights treaty bodies can and will scrutinize inter-State agreements when those agreements risk entrenching human rights violations. Simultaneously, it places pressure on other UN bodies, including the Human Rights Committee and the Committee on the Elimination of Discrimination against Women, which recently declined to register individual communications from Chagossian women (Bernadette Dugasse and Bertrice Pompe) seeking interim protection in the absence of effective domestic remedies—a silence that now stands in uncomfortable contrast to CERD’s principled engagement.

Several avenues may now be pursued. Domestic ratification debates in both the UK and Mauritius will likely need to engage with CERD’s requests, even if the decision is not formally binding. Diplomatic discussions may also evolve, particularly with States that have viewed the UK-Mauritius Agreement as fully aligned with the Advisory Opinion and the General Assembly resolution; CERD’s intervention provides an opportunity to clarify the human rights considerations those instruments leave open. In parallel, regional mechanisms may offer additional forums to explore the legal consequences for States when they negotiate, sign and ratify treaties with former colonial powers that affect access to reparations, the right to return, and the effective exercise of self-determination.