Diego Garcia, coral island, 11 sq mi (28 sq km). Indian Ocean, largest island of the Chagos Archipelago, SW of Sri Lanka. Part of the British Indian Ocean Territory, the island was leased (1970) to the United States and later developed as a joint U.S.-British naval base to guard the Persian Gulf oil routes and to counter increased Soviet military activities in S Asia and Africa. Some 3,000 islanders were removed to Mauritius and the Seychelles in the late 1960s prior to the construction of the naval base. The military base has had significant strategic value as a staging area in the conflicts in Iraq and Afghanistan.
See study by D. Vine (2009).