On Sunday, the United States hit back with airstrikes at Kata’ib Hezbollah — an Iranian proxy militia — in Iraq and Syria. The airstrikes were in retaliation to the terrorist group’s hit of a U.S. base outside Kirkuk, Iraq, with a missile attack on Friday. The attack killed one contractor and wounded four American soldiers.

The attack on the joint U.S/Iraqi Security Forces base was the 11th rocket attack on the U.S. forces in Iraq in the past two months.

The U.S. airstrikes, called “defensive strikes” by the Pentagon, targeted Kata’ib Hezbollah in both Iraq and Syria with five different strikes, hitting three locations in Iraq and two in Syria. At least 18 militant fighters were killed, including four local commanders, and 50 were wounded. 

The U.S. used F-15s to hit all five targets. The targets were used for weapons-storage facilities and command-and-control locations that the Iranian-backed militant organization used to plan and execute attacks on coalition forces, Pentagon officials said.

Jonathan Hoffman, the Assistant to the Secretary of Defense for Public Affairs, said that Kata’ib Hezbollah “has repeatedly received lethal aid and other support from Iran that it has used to attack OIR coalition forces.”

“The OIR coalition is in Iraq at the invitation of the Iraqi government to ensure the lasting defeat of ISIS and provide advice and assistance to the ISF,” he added. “The U.S. and its coalition partners fully respect Iraqi sovereignty and support a strong and independent Iraq. The U.S., however, will not be deterred from exercising its right of self-defense.” 

Kata’ib Hezbollah was labeled a foreign terrorist organization by the U.S. in 2009. It receives the vast majority of its support from Iran. It has been responsible for numerous IED bombings against U.S. and Iraqi forces in the region.

Iran has a myriad of proxy forces in the region. It uses them to escape culpability for the violence that it brings. Repeated U.S. warnings to Tehran to reign in on these proxy forces have fallen on deaf ears.

The official U.S. policy has thus far been one of restraint. 

But now at least, Washington is taking a page out of the Israeli playbook and hitting back hard at these proxy forces. Whether the official policy will change now is not known. The ball is in Tehran’s court. But its bellicose intentions have been apparent for some time: Iran has been quite willing, short of an all-out conflict, to use its proxies in order to further its strategic and tactical aims.