U.S. airstrike in Syria: What comes next?

WASHINGTON — A U.S. airstrike against a Syrian camp used by Iranianbacked militants accused of attacking American bases was a message from President Joe Biden that such attacks would not go unpunished, Pentagon officials said Friday.

What meaning Tehran took from the attack on its proxies remains unclear.

Biden is hoping to draw Iran into negotiations on reviving a 2015 agreement that restricts Tehran’s nuclear program — one that was abandoned by the Trump administration. That goal led to intense debate within Biden’s national security team over choosing a target that would not spark an escalating military conflict with Iran, officials said.

Asked what message he was sending to Iran with an airstrike in Syria, Biden told reporters in Houston on Friday: “You can’t act with impunity. Be careful.”

The predawn Friday attack by two U.S. warplanes destroyed nine buildings and damaged two others at the camp near the IraqSyria border town of Deir al-Zor, Pentagon press secretary John Kirby told reporters.

U.S. officials said multiple groups used the camp to move weapons and personnel into Iraq. Those included Kataeb Hezbollah and Kataeb Sayed AlShuhadaa, two Iranianbacked militias that the Pentagon believes is responsible for recent attacks, including a Feb. 15 rocket barrage on a U.S. base in Irbil that killed a contractor and wounded several service members and contractors.

Casualties from the U.S. attack on Friday were still being assessed, Kirby said. Iraqi officials have said the bombing caused at least one fatality and wounded four, though some estimates from online accounts associated with militias said as many as 17 people had been killed.

The limited strike in eastern Syria was meant to signal the Iranians that the U.S. would not ignore attacks by Iranian proxies but was not seeking a wider military confrontation, officials said. It was no accident that the U.S. struck what amounted to a base used by the militias, an equivalent target to their attacks on the American facilities, officials said.

“This really was a defensive strike ... to try to make an impact on these groups and their ability to conduct future attacks and to send a very clear signal that the United States is going to protect its people,” Kirby said Friday.

The U.S. has offered no evidence that Tehran ordered the attacks on American facilities, and some officials believe the militias may have carried them out on their own.

“The Biden team is saying, ‘Even though we’re highly committed to reestablishing dialogue with the Iranians, we can undertake military strikes at the same time,’” said Michael Knights, an analyst at the Washington Institute for Near East Policy.