NAVAL SUPPORT FACILITY DIEGO GARCIA

OVERVIEW

Naval Support Facility Diego Garcia is the United States military's only installation in the central Indian Ocean — a remote V-shaped coral atoll in the Chagos Archipelago, roughly 1,000 nautical miles south of India and almost equidistant from the Persian Gulf, East Africa, and Southeast Asia. The base sits on British sovereign territory leased to the U.S. under a 1966 Exchange of Notes, making it one of the few overseas U.S. installations operated jointly with another sovereign rather than within a host nation.

The atoll's strategic value comes from its position and isolation. Diego Garcia anchors Maritime Prepositioning Ships Squadron Two — a flotilla of cargo vessels loaded with equipment, ammunition, and supplies sufficient to outfit a Marine Expeditionary Brigade for 30 days of combat operations. The 12,000-foot runway accommodates B-1, B-2, and B-52 bombers, KC-135 and KC-10 tankers, and heavy airlift, and has supported every major U.S. combat operation in Southwest Asia since Desert Storm. The 24-square-kilometer lagoon provides a sheltered deepwater anchorage for fleet auxiliaries, submarine tenders, and visiting warships.

Approximately 1,700 U.S. military, civilian, and Department of Defense personnel are stationed on Diego Garcia, alongside a contract workforce drawn from Mauritius, the Philippines, and Sri Lanka. The island has no permanent civilian population and no commercial flights — access is restricted to authorized military and government travelers.

KEY FACTS

• Only U.S. Indian Ocean BaseSole U.S. military installation in the central Indian Ocean basin
• Strategic AnchorHub for maritime prepositioning and long-range bomber operations supporting CENTCOM and INDOPACOM
• Joint U.K.–U.S. OperationBritish sovereign territory leased to the United States under a 1966 Exchange of Notes
• Lease ExtensionRenewed in 2016 for 20 years, running through December 2036
• FootprintV-shaped coral atoll roughly 60 km long with 6,720 acres of land and a 24 km² lagoon anchorage

HISTORY

Diego Garcia's modern military history began in 1965, when the United Kingdom separated the Chagos Archipelago from the colony of Mauritius and established the British Indian Ocean Territory (BIOT). In 1966, London and Washington signed an Exchange of Notes that made BIOT available for joint U.S.–U.K. defense purposes for 50 years, with a 20-year extension option. Between 1968 and 1973, the British government removed the indigenous Chagossian population — a forced displacement that remains the subject of ongoing legal and political dispute, including 2019 advisory opinions from the International Court of Justice and the U.N. General Assembly affirming Mauritian sovereignty claims. In October 2024, the U.K. announced an agreement in principle to transfer sovereignty over the Chagos Archipelago to Mauritius while preserving long-term U.S. operational use of Diego Garcia under a separate lease.

Construction of a U.S. Navy Communications Station began in 1971, and Naval Support Facility Diego Garcia was formally established in 1973. Through the 1970s and early 1980s the island grew from a modest communications outpost into a full naval support facility, with deepwater piers, a 12,000-foot runway, fuel storage, and an anchorage capable of supporting an entire prepositioning squadron.

Diego Garcia took on strategic prominence during Operation Desert Shield and Desert Storm in 1990–91, when B-52 Stratofortress bombers flew the longest combat missions in history from the island to targets in Iraq, and Maritime Prepositioning Ships Squadron Two sortied to deliver Marine Corps equipment to Saudi Arabia within days of the Iraqi invasion of Kuwait. After September 11, 2001, the base became the principal long-range bomber hub for Operation Enduring Freedom in Afghanistan and later Operation Iraqi Freedom, hosting rotational deployments of B-1B Lancers, B-2 Spirits, and B-52H Stratofortresses, plus KC-135 and KC-10 tankers of the 36th Expeditionary Wing.

Today, Diego Garcia is operated by Commander, Naval Support Facility Diego Garcia under Commander, Navy Region Hawaii, and supports Commander, Task Force 53 (the Indian Ocean prepositioning task force) along with rotational U.S. Air Force, Royal Air Force, and Royal Navy detachments. The 2016 extension of the U.S.–U.K. agreement secured American operational access through December 2036, and the 2024 U.K.–Mauritius framework anticipates that access continuing under a renegotiated long-term lease regardless of the eventual sovereignty outcome.

MAJOR COMMANDS & TENANT UNITS

• Commander, Naval Support Facility Diego Garcia (NAVSUPPFAC DG)
• Commander, Task Force 53 — Maritime Prepositioning Ships Squadron Two (MPSRON 2)
• Detachment, U.S. Air Force 36th Expeditionary Wing (rotational bomber and tanker operations)
• Naval Computer and Telecommunications Station (NCTS) Far East Detachment Diego Garcia
• Defense Logistics Agency Energy Diego Garcia

LOCATION & GEOGRAPHY

HOST NATION CONTEXT

Diego Garcia is unique among major U.S. overseas installations in that the host nation is not a sovereign country in the traditional sense, but rather the British Indian Ocean Territory (BIOT) — a U.K. overseas territory administered from London. U.S. forces operate under the 1966 U.S.–U.K. Exchange of Notes, which made the entire archipelago available for joint defense purposes for 50 years. The 2016 extension carries the agreement through December 2036.

In October 2024, the United Kingdom announced an agreement in principle to transfer sovereignty over the Chagos Archipelago, including Diego Garcia, to Mauritius. The accord — still being finalized — explicitly preserves long-term U.S. operational use of Diego Garcia under a renegotiated 99-year lease, and the United States has publicly endorsed the arrangement as protective of its strategic equities. The eventual implementation will leave day-to-day U.S. operations effectively unchanged while resolving a long-running sovereignty dispute traced back to the 1968–1973 forced removal of the indigenous Chagossian population.

Personnel arriving at Diego Garcia clear customs and immigration as guests of the U.K. BIOT administration, not under a conventional bilateral SOFA. Civilian contractors are recruited from Mauritius, the Philippines, and Sri Lanka under U.S. and U.K. labor arrangements. There is no host-nation civilian community, no consulate, and no public access to the island.

NOTABLE EVENTS

1. 1966
   U.S.–U.K. Exchange of Notes

   United States and United Kingdom sign agreement permitting U.S. military use of Diego Garcia for 50 years, with an option to extend.
2. 1971
   Communications Station

   Construction begins on a U.S. Navy Communications Station — first permanent U.S. presence on the island.
3. 1986
   Maritime Prepositioning

   Diego Garcia becomes the principal anchorage for Maritime Prepositioning Ships Squadron Two, prepositioning equipment for a Marine Expeditionary Brigade.
4. 1991
   Operation Desert Storm

   B-52 Stratofortress bombers fly long-range missions against Iraqi targets from Diego Garcia — first combat use of the runway.
5. 2001
   Operation Enduring Freedom

   B-1, B-2, and B-52 bombers operate continuously from Diego Garcia in support of operations in Afghanistan.
6. 2016
   Lease Extension

   U.K. and U.S. extend the 1966 agreement for an additional 20 years, securing access through December 2036.

NEARBY BASES

FREQUENTLY ASKED QUESTIONS

SOURCES

• Wikipedia: Diego Garcia
• CNIC — Naval Support Facility Diego Garcia
• U.K. Foreign, Commonwealth & Development Office — British Indian Ocean Territory
• International Court of Justice — Chagos Archipelago Advisory Opinion (2019)