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

Describing Iran’s missile strike on an American airbase near Doha as an act of self-defense, Spokesperson for the Iranian Foreign Ministry Esmaeil Baqaei said the attack had nothing to do with Qatar.

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