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 his 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.
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 United Kingdom to end its "colonial administration" of the islands and transfer sovereignty to Mauritius.