US forces hammered dozens of IRGC and Iran-backed militia targets with 125 bombs in retaliation for the drone attack that killed American troops

• US forces on Friday conducted strikes against Iran-backed groups.
• The military action comes days after a drone attack killed US troops in Jordan.

The US military on Friday began strikes against Iran-backed militias in Iraq and Syria, a US defense official told Business Insider. It is expected to be part of a larger retaliatory campaign.

After the initial news broke, US Central Command, or CENTCOM, released a statement that said numerous aircraft, including long-ranger bombers, conducted airstrikes against Iran's Islamic Revolutionary Guards Corps (IRGC) Quds Force and affiliated militia groups in Iraq and Syria. It said more than 125 precision munitions were used to hit over 85 targets in the two countries.

"The facilities that were struck included command and control operations centers, intelligence centers, rockets, and missiles, and unmanned aerial vehicle storages, and logistics and munition supply chain facilities of militia groups and their IRGC sponsors who facilitated attacks against US and Coalition forces," CENTCOM said in its statement.

White House National Security Council spokesperson John Kirby told reporters that the strikes hit seven facilities used by the IRGC and affiliated militia groups in Iraq and Syria, and the military action lasted 30 minutes. The number of casualties is unclear, but he said the strikes are believed to be "successful."

President Joe Biden said that while the US response began on Friday, "it will continue at times and places of our choosing."

"The United States does not seek conflict in the Middle East or anywhere else in the world," he said in a statement. "But let all those who might seek to do us harm know this: If you harm an American, we will respond."

The retaliatory action comes days after a drone struck a small US military outpost in northeast Jordan. It struck the living quarters for American troops, killing three and injuring dozens, some of whom had to be evacuated from the country to higher level care. The Pentagon said in the aftermath that it expected the number of wounded individuals to fluctuate as people seek follow-on care.

The White House immediately blamed Iran-backed militias for the deadly incident and vowed revenge. "Have no doubt — we will hold all those responsible," Biden said at the time.

Echoing Biden's remarks, Secretary of Defense Lloyd Austin said "the President and I will not tolerate attacks on American forces, and we will take all necessary actions to defend the United States, our troops, and our interests."

Washington also signaled throughout the week that there won't be a single act of retaliation, but rather the US response will have multiple layers to it.

"The first thing you see won't be the last thing," Kirby said at a Jan. 31 briefing.

The Jan. 28 attack marked the first American fatalities since mid-October, when Iran-backed militias began relentlessly attacking US forces across Iraq and Syria and is a significant escalation from the previous incidents.

The Pentagon has retaliated on a handful of occasions to these attacks — which total more than 160 and have featured a mix of drones, rockets, and missiles — by conducting strikes targeting Tehran-linked assets in Iraq and Syria.

Analysts at the Institute for the Study of War have said that while the militias describe their attacks as a response to Israel's fight against Hamas, they're actually part of Iran's longstanding foreign policy goal of expelling US forces from the Middle East. Tehran also supports proxies in Gaza, Lebanon, and Yemen — Hamas, Hezbollah, and the Houthis, respectively.

The US base at the Jordan border directly supports approximately 900 US troops at outposts in Syria. The recent drone attack could have been an attempt to undermine the US hold in eastern Syria and to open arms smuggling routes through Jordan to the West Bank.

Some US lawmakers have called for the Biden administration to take aggressive military action in retaliation for the Jan. 28 drone attack, including conducting strikes inside Iran itself. Tehran's foreign ministry initially denied any involvement in the deadly attack and said the militia groups it supports make their own decisions. Iran has also threatened to respond if attacked.

Update: February 2, 2024 — This article has been updated with statements from CENTCOM and President Joe Biden, as well as additional comments from the White House.