Chagos Treaty Pause
1) Context:
The U.K. has paused legislation operationalising a treaty signed in May 2025 to transfer sovereignty over the Chagos Archipelago to Mauritius, pending discussions with the U.S. The treaty proposes Mauritian sovereignty with a 99-year U.K. lease over Diego Garcia for the joint U.K.–U.S. military base.
2) Chagos Archipelago & Diego Garcia
2.1 Chagos Archipelago
• Group of 60+ islands in the central Indian Ocean.
• Strategically located between Africa and Southeast Asia.
• Administered by the U.K. as the British Indian Ocean Territory (BIOT).
2.2 Diego Garcia
• Largest island in the archipelago.
• Hosts a major U.K.–U.S. military base (critical for Indo-Pacific and West Asian operations).
• Currently under U.K. control; base operated jointly with the U.S.
3) Chronological Background
3.1 Colonial Phase (Pre-1965)
Chagos was administered as part of British colonial Mauritius under the British Empire.
3.2 1965 – Creation of BIOT
Before granting independence to Mauritius, the U.K. detached Chagos and created the British Indian Ocean Territory (BIOT).
3.3 1966 – U.S.–U.K. Agreement
U.K. leased Diego Garcia to the U.S. for military use.
Chagossians were displaced between 1968–1973.
3.4 1968 – Mauritius Independence
Mauritius gained independence, but without Chagos; it has since claimed sovereignty.
3.5 UN Developments
• 2017: United Nations General Assembly requested an advisory opinion from the ICJ.
• 2019: International Court of Justice ruled that the U.K.’s separation of Chagos was unlawful and decolonisation was incomplete.
• 2019 (UNGA Resolution): Called on the U.K. to withdraw administration within six months.
The U.K. initially rejected the ruling but later entered negotiations with Mauritius.
4) Recent Shift 2022–2025:
• U.K.–Mauritius negotiations progressed.
• Treaty signed (May 2025) to transfer sovereignty to Mauritius while leasing Diego Garcia back to the U.K. for 99 years to ensure continued U.S. base access.
• Implementation paused pending U.S. consultations.
