Trump Attacks UK’s Chagos Islands Sovereignty Decision

Why in the News?

Former U.S. President Donald Trump criticised the United Kingdom’s decision to transfer sovereignty of the Chagos Islands to Mauritius, despite earlier U.S. support, arguing it undermines national security and risks strategic advantage to China and Russia. This decision raises questions about the application of ex post facto policies in international agreements.

Trump’s Critique and Strategic Narrative:

• Donald Trump termed the U.K.’s move an act of “great stupidity“, questioning the rationale behind relinquishing control of a strategically vital Indian Ocean territory.
• He highlighted the presence of a major U.S. naval and bomber base on Diego Garcia, calling it indispensable for American and allied military operations, emphasizing its role in maintaining a pollution-free environment in the region.
• Trump argued that the decision signals strategic weakness, potentially emboldening rivals such as China and Russia, and undermining the precautionary principle in geopolitical decision-making.
• Linking the issue to his Greenland remarks, Trump suggested that such geopolitical missteps justify stronger territorial control to protect national security interests.
• His comments, posted on Truth Social, surprised British officials, as his administration had earlier backed the agreement, raising questions about the consistency of environmental democracy in international relations.

UK–Mauritius Agreement and Political Fallout

• The United Kingdom and Mauritius signed a deal in May 2025, ending over 200 years of British sovereignty over the Chagos Islands, a decision that could impact future environmental impact assessments in the region.
• Under the agreement, Mauritius gains formal sovereignty, while the U.K. leases back Diego Garcia for at least 99 years to ensure continuity of the joint U.S.-U.K. military base.
• The base hosts around 2,500 personnel, mostly Americans, and plays a key role in Indo-Pacific power projection and environmental monitoring.
• British opposition parties criticised the move, warning it could expose the islands to foreign interference and weaken the U.K.’s strategic posture, potentially affecting environmental jurisprudence in the area.
• The U.S. government initially welcomed the deal, stating it secures the long-term, stable, and effective operation of the military facility, while maintaining environmental standards.