National Interest

by Azeem Ibrahim

    Ceding the islands to a smaller nation and leasing back Diego Garcia, home to a key US and UK military base, comes with long-term risks.

    President Donald Trump’s recent warning to Prime Minister Keir Starmer over the proposed Chagos Islands deal is not bluster. It is a strategic intervention at precisely the right moment. If anything, it may have saved Britain from one of the most consequential geopolitical miscalculations of the postwar era.

    /Donald Trump’s Feb. 18, 2026 Truth Social post about the Chagos Islands deal. (Screenshot)

    The US and the UK have shared a military base on Diego Garcia, the largest island in the Chagos Islands, since the 1970s. As I previously argued in the Washington Examiner, Diego Garcia is not an obscure colonial relic but a cornerstone of Western power projection in the Indo-Pacific and Middle East.

    The proposed agreement would see the United Kingdom transfer sovereignty of the Chagos Islands to Mauritius while leasing back the base for nearly a century at a cost reportedly running into the billions. This is being framed in London as a legal tidy-up, a necessary act of post-colonial housekeeping. In reality, it is a profound strategic surrender dressed up as moral rectitude.

    Trump is correct to oppose it for three core reasons: deterrence credibility, alliance coherence and systemic competition with China.

    First, deterrence rests not merely on capabilities but on control. Diego Garcia’s value lies in its political reliability. It has functioned for decades as a secure, uncontested platform for American bombers, naval logistics, intelligence operations and contingency planning. It played pivotal roles in operations in Afghanistan and Iraq and remains critical to Indo-Pacific force posture.

    A sovereign transfer fundamentally alters that equation. Even with a lease agreement in place, legal sovereignty would shift to Mauritius. Leases are political instruments, not immutable guarantees. They are subject to renegotiation, domestic pressure and external influence. Trump’s blunt point that “leases are no good when it comes to countries” reflects a basic geopolitical truth: in great power competition, ambiguity is vulnerability.

    /A map of the Chagos Islands, with Diego Garcia circled. Diego Garcia is the largest island in the archipelago and home to a military base shared by the US and the UK. (Wikimedia Commons/Hogweard)

    Second, the deal fractures alliance logic. The United States and United Kingdom maintain what is often described as the “special relationship,” underpinned by Five Eyes intelligence integration, nuclear cooperation and deeply embedded military interoperability. That relationship presumes strategic alignment.

    If London unilaterally restructures sovereignty over one of the most vital US basing assets in the world without airtight guarantees acceptable to Washington, it introduces avoidable friction into that alignment. Allies do not create strategic uncertainty for one another at the height of systemic competition.

    It is worth recalling that this is not a marginal installation. Diego Garcia sits astride critical sea lanes connecting the Middle East, Africa and Asia. It is one of the few locations from which the United States can project sustained air and naval power across multiple theaters without overflight constraints. In an era in which access is increasingly contested, voluntarily complicating sovereignty arrangements is strategically perverse.

    Third and most importantly, the China factor cannot be ignored. Beijing has demonstrated a consistent pattern of converting economic relationships into strategic leverage. From Hambantota in Sri Lanka to port infrastructure across the Indian Ocean, China’s method is incremental entrenchment.

    Mauritius is not China, nor is it inevitably destined to grant Beijing access. But structural incentives matter. A small state assuming sovereignty over strategically valuable territory will face competing courtships. Over decades, economic inducements, infrastructure investments, or diplomatic pressure can shift political calculations. Even the perception that Chinese influence could grow in proximity to Diego Garcia would complicate US operational planning.

    Great power competition is not fought in dramatic territorial seizures; it is fought in gray zones, through influence, access rights and incremental positioning. Trump’s objection recognizes that once sovereignty is transferred, leverage diminishes. Reversibility becomes politically and legally costly.

    Critics will argue that international legal rulings and decolonization norms require Britain to relinquish the territory. But law does not operate in a vacuum. States routinely balance legal interpretations against security imperatives. Moreover, the proposed solution does not simply resolve a legal dispute; it creates a long-term strategic dependency through a century-long lease arrangement.

    The irony is that in seeking to appear morally forward-looking, the UK risks appearing strategically naïve. Paying billions to lease back territory it already administers while introducing uncertainty into the Western alliance structure is not prudence; it is self-imposed constraint.

    Trump’s intervention does not undermine Britain. It reinforces a shared strategic interest. By signaling that Washington views the deal as unacceptable, he raises the political cost of proceeding and strengthens the hand of those within the United Kingdom who understand the risks.

    In an era defined by fragmentation, contested supply chains and rising middle powers, Western coherence is a competitive advantage. Voluntary dilution of hard power positions in the Indian Ocean makes little sense when China is expanding its naval reach and Iran continues destabilizing regional dynamics.

    This is not about nostalgia for empire. It is about preserving operational certainty in a system where uncertainty is weaponized.

    If the Chagos deal collapses under scrutiny, it will not be because of American heavy-handedness; it will be because strategic logic reasserted itself over legalistic symbolism. In that respect, Trump’s stance may indeed have saved Britain from a costly mistake — and preserved a critical pillar of Western deterrence at a moment when it can least afford erosion.