American warplanes destroyed or severely damaged most of the Iranian and militia targets they struck in Syria and Iraq on Friday, according to the Pentagon, the first major salvos in what President Biden and his aides have said will be a sustained campaign. Gen. Patrick S. Ryder, the Pentagon press secretary, said on Monday that "more than 80" of some 85 targets in Syria and Iraq were destroyed or rendered inoperable. The targets, he said, included command hubs; intelligence centers; depots for rockets, missiles and attack drones; as well as logistics and ammunition bunkers. It was the first military assessment of the strikes carried out in response to a drone attack in Jordan by an Iran-backed militia in Iraq on Jan. 28 that killed three American soldiers and injured at least 40 more service members. "This is the start of our response, and there will be additional actions taken," General Ryder told reporters without elaborating.

A U.S. military surveillance drone was shot down off the coast of Yemen on Wednesday by Iran-backed Houthi rebels, the Pentagon said. Pentagon officials, speaking on the condition of anonymity to discuss operational matters, confirmed that the drone, an MQ-9 Reaper, had been shot down. But they would not say if the aircraft was armed, where it was flying from or other details. The downing of a Reaper drone, the mainstay of the American military's aerial surveillance fleet, was the latest escalation of violence between the United States and Iran-backed groups in Yemen, Iraq and Syria. The episodes have underscored the risks that the conflict between Israel and the Palestinian group Hamas could spiral into a wider war.

According to an American military official, the 358 missile in flight is about nine feet long and can run on kerosene or diesel fuel contained in flexible containers that do not require a separate fuel pump. A dozen infrared lenses arranged in a ring around the missile are believed to be able to defeat heat-seeking countermeasures that coalition helicopters typically use. Another United States military official said that the 358 missiles from Iran had been fired against American drones flying in Yemeni airspace, but they had not yet succeeded in hitting any. Three of the 358 missiles were captured in November by the Forrest Sherman, a Navy destroyer, and five more were recovered this month in an operation by the Normandy, a Navy cruiser. Those shipments also included more than 170 antitank guided missiles made in Iran, as well as 13,000 blasting caps, which are critical to making modern roadside bombs.

The comments of the president, who avoided the Vietnam War draft thanks to a diagnosis of bone spurs, drew swift criticism from veterans groups. "Don't just be outraged by #PresidentMayhem's latest asinine comments," Paul Rieckhoff, the founder of Iraq and Afghanistan Veterans of America, wrote in a Twitter post that day. "Take action to help vets facing TBIs," meaning traumatic brain injuries. Traumatic brain injuries result from the powerful changes in atmospheric pressure that accompany an explosion like that from a missile warhead. The missiles were launched by Iran in retaliation for the killing of a top Iranian general, Qassim Suleimani, by an American drone strike in Baghdad on Jan. 3.