Strategic importance of Diego Garcia

• Iran targeted the joint UK-US Diego Garcia military base in the Indian Ocean about 4,000 kilometers away.

• It suggests that Tehran has missiles that can go farther than previously acknowledged.

• According to reports, neither of the missiles struck the base as they were intercepted. One missile failed mid-flight, and the other was engaged by an interceptor launched from a US warship. 

• It is unclear if there were any damages caused to the flights stationed at the base or whether the warship was hit. 

• The attacks, and threats of more to come, indicate the war shows no sign of abating as its effects are felt far beyond the Middle East, raising food and fuel prices.

Strategic importance of Diego Garcia

• In May 2025, the United Kingdom signed an agreement to hand sovereignty over the Chagos Islands to Mauritius, resolving a long-standing colonial-era dispute.

• The Indian Ocean archipelago is home to an important naval and bomber base on the largest of the islands, Diego Garcia, operated by US forces and crucial for British counter-terrorism and intelligence.

• The multibillion-dollar deal will allow Britain to retain control of the strategically important US-UK air base on Diego Garcia, the largest island of the archipelago in the Indian Ocean, under a 99-year lease.

• Under the agreement, the UK will pay Mauritius an average of 101 million pounds ($136 million) a year to lease back the base for at least 99 years.

• The deal ensures the UK retains full operational control of Diego Garcia, including management of the electromagnetic spectrum satellite used for communications – vital for countering hostile interference.

• The base provides a unique shared platform with irreplaceable security capabilities that enable a UK and US military presence across the Middle East, Indo-Pacific and Africa.

• The base has played a vital role in defending the UK and its allies for over 50 years. 

• Its deep-water port, airfield, and advanced communications and surveillance capabilities give the UK and its allies crucial strategic capabilities, which have played a key role in missions to disrupt high-value terrorists.

• The base is a critical logistics hub at a strategic location, with a full range of facilities that acts as a key refuelling and resupply station for naval and air operations.

• The base helps protect some of the most important shipping lanes in the world, while also remaining isolated enough to be protected from attack by adversaries.

Base capabilities

Airfield: Location and infrastructure accommodate a broad range of military aircraft, with capability to support military requirements from strike operations to humanitarian response.

Port: A multitude of berthing options for the UK and US navies to support various missions including Carrier Strike Group deployment. The UK maintains a Nuclear Emergency Response Organisation to permit nuclear powered submarines to safely berth at the port. The US uses Diego Garcia to strategically position equipment and supplies at sea for rapid deployment in various global theatres, including for humanitarian aid and disaster relief missions over the years, across the Indo-Pacific.

Seismic monitoring: Permanent location of three pieces of critical Comprehensive Nuclear Test Ban Treaty monitoring equipment, a network constantly monitoring for indicators of nuclear testing, vital in preventing nuclear proliferation.

Space capabilities: Hosts one of the monitoring stations and one of the four ground antennas for the Global Positioning System (GPS). Also hosts part of the Ground-Base Electro-Optical Deep Space Surveillance (GEODSS) System. This provides situational awareness of objects in Earth’s orbit, helping to track space debris that pose a risk to space systems.