Iran retaliated against the U.S. on Monday, launching missiles at a U.S. base in Qatar, according to a U.S. defense official and a statement from the Qatar foreign ministry. The missiles targeted Al Udeid Air Base outside Doha and were intercepted by air defenses before they could strike the base,

One of the largest U.S. bases in the Middle East was attacked Monday by an Iranian missile strike just days after the U.S. carried out an unprecedented strike on that country's nuclear facilities, the Pentagon said.

The Pentagon already had begun taking measures to strengthen its firepower in the Middle East and protect U.S. bases there.