Why is the US-UK Diego Garcia military base in the Chagos Islands a target for Iran?

Iran fired a missile at a joint US-UK base in the Indian Ocean, warning that British lives were “in danger” after Prime Minister Sir Keir Starmer backed the US to carry out more attacks.

Tehran fired two medium-range ballistic missiles at Diego Garcia in the Chagos Islands, but neither hit. It was reported that one of the missiles was shot down by a US warship and the other could not fly.

The attack is understood to have come before Downing Street said on Friday that UK bases would now be used for US “defensive operations to disrupt missile sites and capabilities used to attack ships”.

On Saturday, the Ministry of Defense condemned the attack as “reckless”.

Diego Garcia is about 3,360 miles from Iran and hosts an air base that can accommodate long-range U.S. bombers, with about 2,500 American troops stationed on the island.

Britain agreed to transfer sovereignty of the islands to Mauritius and lease back the base, a move that has strained relations with Washington in recent months.

Diego Garcia is strategically valuable to the United States and has been used as a launchpad for operations in the Middle East for years; Donald Trump calls the deal a “big mistake.”

Why is there a UK-US base in Diego Garcia?

At the end of World War II, as more countries became independent from colonialism, concerns began to grow within the U.S. administration about their diminishing access to overseas bases.

It has been suggested that the Diego Garcia base will allow the United States to create power in the region, as naval planners are concerned about the possibility of Russia and China gaining a stronger foothold in the Indian Ocean.

Given that the United Kingdom had established a base here during the war and remained in administrative status, it was decided in 1961 that the British government would separate the Chagos Archipelago from colonial Mauritius for future military use.

After secret negotiations, the US agreed to pay the British up to $14 million for its use.

A Chatham House report stated: “Since then, the military base at Diego Garcia has served as a mainstay for American operations.

“The island hosts a large airfield with runways long enough to accommodate large military aircraft such as B-52 bombers, KC-135 tankers, reconnaissance aircraft, and transport aircraft. It also has large fuel storage facilities, radar facilities, and control towers that can support regional military operations.”

It was a critical launch pad for U.S. air operations during the 1991 Gulf War and the 2003 Iraq War.

How will Britain’s plans to hand over the Chagos Islands to Mauritius affect the base?

The government argued that the agreement was necessary to guarantee the future of the Diego Garcia base after the International Court of Justice’s advisory ruling in 2019 supported Mauritius’ sovereignty claims over the islands.

According to the plan, the UK will pay a nominal £34.7 billion over 99 years to secure the use of the base.

However, the legislation allowing the handover has not been passed by the Parliament since January 20, although it is in the final stages.

The agreement faced significant criticism in both Westminster and the White House; Parties such as Reform UK and the Conservatives heavily criticized the decision.

What did Trump say about this?

The £35bn deal, which includes a plan to lease back the strategically important UK-US military base on Diego Garcia, the largest island in the remote Indian Ocean archipelago, has sparked barbed exchanges in Westminster and a sudden change of heart from the American leader.

While the US administration initially hailed the deal as a “tremendous achievement”, Mr Trump later criticized it as “an act of gross stupidity” and “sheer weakness” amid transatlantic tensions over his ambition to annex Greenland.

The US president later signaled his support for the deal, saying it was the “best” thing Prime Minister Sir Keir Starmer could have done.

But it recently withdrew its support for the deal, calling it a “big mistake” because Britain refused to use its military bases in a US attack on Iran.

Britain announced that it would not continue the agreement unless there was support from the United States.

Speaking outside the White House on Friday, Mr Trump said: “There was a very late response from the UK.

“I’m surprised how good the relationship is, but this has never happened before.

“They were truly our first ally anywhere in the world.”

Referring to Diego Garcia, he said: “For some reason they did not want us to use the so-called island to which they had given up their rights.

“To be honest, I was a bit surprised in the UK. They should have moved a lot quicker.”

Could Iranian missiles really hit a UK base?

As the UK is drawn further into the conflict, some in Britain are naturally concerned about the potential for fallout to reach the mainland.

Experts say this is unlikely because Iran’s strike capabilities have not been assessed long-term enough to complete the 3,000-mile journey.

Vuk Vuksanović, of foreign policy think tank LSE IDEAS, said: “There is no evidence that Iran has the capacity to attack the US or UK mainland.

“With its missile and unmanned aerial vehicle capabilities, Iran has the capacity to strike US and UK military outposts in the Middle East, including the Gulf and the Levant.”

This includes RAF Akrotiri base in Cyprus and Diego Garcia base, which are currently targeted by drones.

But analysts estimated that Iran’s longest-range weapon was the Khorramshahr 4 missile, which could potentially hit targets 1,200 to 3,900 miles away.

Given the success of launching ballistic missiles against the Chagos Islands, it is feared that Iran is more capable than assumed.