Britain condemned “Iran’s reckless attacks” after the unsuccessful attempt to hit the base. It’s unclear how close the missiles came to the island, which is about 2,500 miles (4,000 kilometers) from Iran.

Here is what to know about the remote but strategic base.

Hub for US operations

The United States has described the Diego Garcia base as “an all but indispensable platform” for security operations in the Middle East, South Asia and East Africa.

Home to about 2,500 mostly American personnel, it has supported U.S. military operations from Vietnam to Iraq and Afghanistan. In 2008, the U.S. acknowledged that it also had been used for clandestine rendition flights of terror suspects.

The U.S. deployed several nuclear-capable B-2 Spirit bombers to Diego Garcia last year amid an intense airstrike campaign targeting Yemen’s Houthi rebels.

Britain initially refused to let the base be used for U.S-Israeli attacks on Iran, but after Iran lashed out at its neighbors, the United Kingdom said American bombers could use Diego Garcia and another British base to attack Iran’s missile sites. On Friday, the U.K. government said that includes sites being used to attack ships in the Strait of Hormuz.

The U.K. says that the British bases can only be used for “specific and limited defensive operations.”

But Iranian Foreign Minister Abbas Araghchi said on X that U.K. Prime Minister Keir Starmer “is putting British lives in danger by allowing UK bases to be used for aggression against Iran.”

Iran previously has put a self-imposed limit on its ballistic missile program, limiting their range to 1,240 miles (2,000 kilometers). Diego Garcia is well outside that range. However, U.S. officials long have alleged Iran’s space program could allow it to build intercontinental ballistic missiles.

Justin Bronk, a senior research fellow at defense think tank the Royal United Services Institute, said that the attempt to hit Diego Garcia may have involved improvised use of Iran’s Simorgh space launch rocket, “which could offer greater range as a ballistic missile,” though at the cost of reduced accuracy.

A contested island chain

Diego Garcia is part of the Chagos Archipelago, a chain of more than 60 islands in the middle of the Indian Ocean off the tip of India. The islands have been under British control since 1814, when they were ceded by France.

In the 1960s and 1970s, Britain evicted as many as 2,000 people from Diego Garcia, so the U.S. military could build the base there.

In recent years, criticism has mounted over Britain’s control of the archipelago and the way it forcibly displaced the local population. The United Nations and the International Court of Justice have urged the U.K. to end its “colonial administration” of the islands and transfer sovereignty to Mauritius.

Trump criticism

After long negotiations, the U.K. government struck a deal last year with Mauritius to hand over sovereignty of the islands. Britain would then lease back the Diego Garcia base for at least 99 years.

The U.K. government says that will safeguard the future of the base, which is vulnerable to legal challenges. But the agreement has been criticized by many British opposition politicians, who say giving up the islands puts them at risk of interference by China and Russia.

Some of the displaced Chagos islanders and their descendants also have challenged the deal, saying they weren’t consulted and it leaves them unclear on whether they will ever be allowed to return to their homeland.

The U.S. administration initially welcomed the deal, but U.S. President Donald Trump changed his mind in January, calling it “an act of GREAT STUPIDITY” on his social media platform Truth Social.

Starmer’s initial refusal to let the U.S. attack Iran from Diego Garcia further angered Trump, who said earlier this month that “the U.K. has been very, very uncooperative with that stupid island that they have.”

Passage of the U.K.-Mauritius deal through Parliament has been put on hold until U.S. support can be regained.