US strikes have hit most targets in Iraq and Syria, the Pentagon says

US warplanes destroyed or seriously damaged most of the Iranian and militia targets they struck in Syria and Iraq on Friday. According to the Pentagon, these are the first major salvos in what President Biden and his aides have said will be a sustained campaign.

Maj. Gen. Patrick S. Ryder, the Pentagon's press secretary, said Monday that “more than 80” of about 85 targets in Syria and Iraq had been destroyed or disabled. The targets, he said, included command centers; intelligence centers; missile, missile and attack drone depots; as well as logistics and ammunition bunkers.

It was the first military assessment of the strikes carried out in response to a drone strike in Jordan by an Iran-backed militia in Iraq on Jan. 28 that killed three U.S. soldiers and injured at least 40 service members.

“This is the beginning of our response and additional actions will be taken,” General Ryder told reporters, without elaborating. “We do not seek conflict in the Middle East or anywhere else, but attacks on American forces will not be tolerated.”

But the assessment also shows the limits of the US campaign so far. In particular, U.S. officials acknowledge that militia targets still retain most of their ability to launch future attacks.

There was no initial indication that Iranian advisers were killed in the strikes on Friday, military officials said, but General Ryder said there were likely casualties. Syria and Iraq said at least 39 people — 23 in Syria and 16 in Iraq — were killed in Friday's strikes, a toll that the Iraqi government said included civilians.

The attacks in the two countries, as well as US-led strikes on Saturday against 36 Houthi targets in northern Yemen, have pushed the region closer to a wider conflict, even as the government insists it does not want war with Iran. Instead, U.S. officials say they are focused on eliminating the militias' formidable arsenals and deterring additional attacks on U.S. troops and merchant ships in the Red Sea.

The militias, however, seem undeterred. Hours after the attacks on Friday, an Iran-backed militia fired two missiles at a US military outpost in northeastern Syria where troops are helping to wipe out the remnants of Islamic State. On Sunday, an explosives-laden drone was fired at another US outpost in northeastern Syria. The missiles caused no damage or American injuries, the Pentagon said. On Sunday, the military's Central Command said US forces had destroyed five Houthi land-based cruise missiles and anti-ship cruise missiles that posed an imminent threat.

In total, Iran-backed militias have carried out at least 166 drone, rocket and rocket attacks on US forces in Iraq, Syria and Jordan since Hamas's Oct. 7 attacks that killed 1,200 people in Israel. The Houthis have carried out at least three dozen attacks on ships in the Red Sea and Gulf of Aden. The militia says its attacks are in solidarity with Palestinians in the war between Israel and Hamas.

National security experts and officials say privately that to truly reduce the capabilities of Shiite militias, the United States would need to wage a years-long campaign similar to the six-year effort to defeat the Islamic State in Iraq and Syria. Even then, officials say, the militias, with Iran's support, could likely outlast Islamic State, which has been under pressure from the United States and Iran, and even Russia.

U.S. officials warned this weekend and Monday that more strikes are planned in what is emerging as an open-ended campaign, not just in Yemen — where the United States and Britain launched their first major retaliatory strikes on Jan. 11 launched – but now also in Yemen. Syria and Iraq to avenge the deaths of three army reservists, who were killed at a remote supply base.

“The president was clear when he ordered them and when he led them that this was the beginning of our response and that there will be more steps to come,” Jake Sullivan, the national security adviser, said on CNN's State of the Union. On Sunday we talked about the strikes in Iraq and Syria.

Mr. Sullivan said he did not want to “pull our punches” by revealing details of future actions. But he said the goal was to punish those who target the Americans without sparking a direct confrontation with Iran.

Analysts say there are already signs that the latest strikes are having an impact in Tehran, where a deeply unpopular government already struggling with a weak economy, outbursts of mass protest and terrorism has little appetite for all-out war with the United States.

But regional specialists say reining in Iran's allies, who depend on Tehran for weapons, intelligence and financing, could prove more difficult.

“Around 2020, Iran began giving these groups blanket permission to attack U.S. positions in Iraq and Syria,” Gen. Kenneth F. McKenzie Jr., a retired head of U.S. Central Command, said on CBS's “Face the Nation” on CBS . Sunday. “They have the ability to carry out these attacks without going straight back to Iran.”

A key question for Mr. Biden and his national security aides is what additional targets in Iraq and Syria could be hit.

On Friday, U.S. B-1B bombers and other warplanes struck targets in four locations in Syria and three locations in Iraq in a 30-minute strike, U.S. officials said. John F. Kirby, a spokesman for the National Security Council, said the targets in each location were selected because they were related to specific attacks on U.S. forces in the region and to avoid civilian casualties.

By avoiding targets in Iran, the White House and Central Command are trying to send a message of deterrence while containing escalation, U.S. officials said. Statements from the White House and Tehran make it clear that neither side wants a broader war. But as the strike in Jordan has shown, with any military action there is the potential for miscalculation.

Helene Kuiper reporting contributed.