U.S. Strikes Iran-Backed Militias in Syria

On February 25, the United States conducted airstrikes in eastern Syria against Iran-backed militias in the first military action by the Biden administration. The Pentagon said that warplanes struck “several facilities” used by Kataib Hezbollah and Kataib Sayyid al Shuhada, two Iraqi Shiite militias trained, armed and funded by Iran. The facilities were located near the Abu Kamal border crossing on the Syrian side of the border with Iraq. The exact death toll was unclear; Kataib Hezbollah claimed that one of its fighters was killed, while a Britain-based monitor claimed that at least 22 militants had been killed. On March 1, the Pentagon said that one fighter was killed and two others were injured.

U.S. airstrikes were meant to send an “unambiguous” message, Pentagon spokesperson John Kirby said in a statement on February 25. “President Biden will act to protect American and Coalition personnel,” he added. “At the same time, we have acted in a deliberate manner that aims to de-escalate the overall situation in both eastern Syria and Iraq.” On February 26, a journalist asked President Biden what message he was trying to send to Iran with the strike. “You can’t act with impunity,” he responded. “Be careful.”

Two F-15E Strike Eagle fighters destroyed nine buildings and partially destroyed two others with precision munitions, Kirby said at a press briefing on February 26. The compound was used to transfer advanced conventional weapons, Capt. Bill Urban, spokesman for U.S. Central Command, said in separate remarks.

February 2021 attacksThe airstrikes were in response to three separate rocket attacks against U.S. and partner forces in Iraq earlier in the month. The deadliest attack occurred on February 15, when rockets hit the Erbil Air Base that houses U.S. troops in Iraq’s Kurdistan region. One Filipino contractor was killed, and a U.S. service member and eight other contractors were wounded. An obscure Shiite militia, Saraya Awliyya al Dam (or “Guardians of the Blood”), claimed responsibility for the Erbil attack, but non-government experts said that the name was likely an alias for Asaib Ahl al Haqq, another Iraqi militia with ties to Iran.

Defense Secretary Lloyd Austin said that Iraqi intelligence had helped identify the culprits behind the rocket attacks. “We’re confident that that target was being used by the same Shia militia that conducted the strikes,” he told reporters on February 25. “We allowed and encouraged the Iraqis to investigate and develop intelligence, and that was very helpful to us in refining the target.”

Moscow and Damascus condemned the U.S. military action as a violation of Syrian sovereignty. The United States informed Russia “four to five minutes” before the airstrikes took place, Foreign Minister Sergey Lavrov said. Iranian Foreign Minister Javad Zarif spoke with his Syrian counterpart and urged the United States to “adhere to U.N. Security Council resolutions.”

Since 2011, Iran has played a critical role in helping the Assad regime defeat rebels and jihadi groups in Syria. In addition to providing funding, weapons and military advisors, the Islamic Republic also mobilized some 20,000 fighters from Lebanon, Iraq, Afghanistan and Pakistan to fight in Syria. The Iraqi groups targeted on February 25 were among the plethora of militias supported by Iran. The following are U.S. statements about the strikes with international reaction, timeline of related events, and profiles of Iraqi militias that have attacked coalition forces.


United States

Letter from President Joe Biden to Speaker of the House and President pro tempore of the Senate on Feb. 27, 2021: “At my direction, on February 25, 2021, United States forces conducted a targeted military strike against infrastructure in eastern Syria used by Iran-supported non-state militia groups. 

“Those non-state militia groups were involved in recent attacks against United States and Coalition personnel in Iraq, including the February 15, 2021, attack in Erbil, Iraq, which wounded one United States service member, wounded four United States contractors, including one critically, and killed one Filipino contractor.  These groups are also engaged in ongoing planning for future such attacks.

“In response, I directed this military action to protect and defend our personnel and our partners against these attacks and future such attacks.  The United States always stands ready to take necessary and proportionate action in self-defense, including when, as is the case here, the government of the state where the threat is located is unwilling or unable to prevent the use of its territory by non-state militia groups responsible for such attacks.” 

Statement by Pentagon Press Secretary John Kirby on Feb. 25, 2021: “At President Biden’s direction, U.S. military forces earlier this evening conducted airstrikes against infrastructure utilized by Iranian-backed militant groups in eastern Syria. These strikes were authorized in response to recent attacks against American and Coalition personnel in Iraq, and to ongoing threats to those personnel. Specifically, the strikes destroyed multiple facilities located at a border control point used by a number of Iranian-backed militant groups, including Kaitib Hezbollah (KH) and Kaitib Sayyid al Shuhada (KSS).

“This proportionate military response was conducted together with diplomatic measures, including consultation with Coalition partners. The operation sends an unambiguous message: President Biden will act to protect American and Coalition personnel. At the same time, we have acted in a deliberate manner that aims to de-escalate the overall situation in both eastern Syria and Iraq.”

Remarks by Secretary of Defense Lloyd Austin on Feb. 25, 2021: “There's not much more that I'll be able to add at this point other than the fact that we're confident in the target we went after, we know what we hit. And we’re confident that target was being used by the same Shia militia that conducted the strikes.”

“We are very deliberative about our approach as you would expect us to be. We allowed and encouraged the Iraqis to investigate and develop intelligence, and that was very helpful to us in refining the target."

“It was my recommendation. We’ve said a number of times [that] we will respond on our timeline. And, once again we wanted to be sure of the connectivity and that we had the right targets.”



Remarks by Iranian Foreign Ministry Spokesman Saeed Khatibzadeh on Feb. 26, 2021: The U.S. strike was “illegal aggression.”

Readout after call between Iranian Foreign Minister and Syrian counterpart on Feb. 26, 2021: “The two sides stressed the need of the West to adhere to U.N. Security Council resolutions regarding Syria.”



Statement by Syrian foreign ministry on Feb. 26, 2021: “Syria condemns in the strongest terms the U.S. cowardly attack on areas in Deir al Zor near the Syrian-Iraqi border…This aggression is a negative indication of the policies of the new American administration, which is supposed to adhere to international legitimacy, not to the law of the jungle.”



Remarks by Russian Foreign Minister Sergey Lavrov on Feb. 26, 2021: "Our military were warned four or five minutes before [the airstrike]…Of course, such warnings are of little use when the strike is basically carried out at that moment."

Remarks by Foreign Ministry spokeswoman Maria Zakharova on Feb. 26, 2021: “We strongly condemn such actions… We call for the unconditional respect of the sovereignty and territorial integrity of Syria.”



Statement by the French foreign ministry on Feb. 26, 2021: “In light of these unacceptable attacks, which we have firmly condemned, we stand with our American allies.”



February 15: Some 14 rockets were fired toward Erbil Air Base, which hosts U.S. troops and contractors, in Iraq’s Kurdistan region. Three rockets hit the base and killed a Filipino civilian contractor. One U.S. service member and eight other contractors, including four Americans, were reportedly injured. An obscure Shiite militia, Saraya Awliyya al Dam (or “Guardians of the Blood”), claimed responsibility. The group had previously claimed responsibility for four roadside bombings of Iraqi convoys carrying U.S.-led coalition supplies between August 2020 and February 2021. Experts said the group was likely connected to Asaib Ahl al Haq (or “League of the Righteous”), one of the most powerful Iraqi militias supported by Iran.

February 20: At least four rockets hit Balad Air Base, which houses the headquarters of U.S. defense company Sallyport, north of Baghdad. A South African employed by Sallyport was reportedly wounded. No group claimed responsibility for the attack.

February 22: Two Katyusha rockets fell near the U.S. Embassy in Baghdad. They did not cause any injuries or casualties. No group claimed responsibility.

February 24: General Kenneth F. McKenzie Jr., the head of U.S. Central Command, said that Iran was connected to recent attacks in Iraq’s Kurdistan region and in Saudi Arabia. It would be “very dangerous” for Iranian officials to assume attacks “can be non-attributable in some way back to Iranian policy,” he told a Beirut Institute forum. “We believe that all of this ultimately emanates from Iran.”

February 25: U.S. forces launched airstrikes on infrastructure used by militias supported by Iran in eastern Syria, near the Iraqi border. The Pentagon said that multiple facilities used by groups, including Kataib Hezbollah (or “Brigades of the Party of God”) and Kataib Sayyad al Shuhada (or “The Masters of the Martyrs Brigade’), were destroyed. “We're confident that the target was being used by the same Shia militia that conducted the strikes [in Iraq],” Defense Secretary Lloyd Austin told reporters. “The operation sends an unambiguous message: President Biden will act to protect American and Coalition personnel,” Pentagon Press Secretary John Kirby said. At least 22 fighters were killed when three trucks carrying munitions from Iraq were hit, according to the Syrian Observatory for Human Rights.


Iraqi Militias Supported by Iran

The following are profiles of militias that have been the most aggressive against U.S. forces. All were part of the PMF (Popular Mobilization Forces), an umbrella group of some 60 old and new militias formed in mid-2014 in response to ISIS’ capture of wide swaths of Iraqi territory. 

  • Kataib Hezbollah, or the Brigades of the Party of God (PMF Brigade 45, 56 and 57) dates back to 2004, when the Shiite militias began attacks on the U.S.-led coalition. Five small armed groups united to form Kataib Hezbollah in 2007 under the tutelage of Iran, which provided weapons, funding and military advice; some of its fighters trained in Iran. Its fighters were held responsible for attacks on the U.S.-led coalition in Iraq. After the 2011 U.S. withdrawal from Iraq, Kataib Hezbollah dispatched fighters to defend the Assad regime in Syria at the behest of Iran. Kataib Hezbollah joined the PMF 2014. It has been responsible for some of the deadliest attacks on U.S. forces.
  • Asaib Ahl al Haq, or League of the Righteous (PMF Brigade 41, 42 and 43, also known as the Khazali Network) was founded in Iraq in 2006. AAH was an off-shoot of Muqtada al Sadr’s Mahdi Army. It was initially equipped, funded and trained by the Islamic Revolutionary Guard Corps (IRGC) Qods Force, with support from Lebanese Hezbollah, in Iranian camps. It became one of the largest and most prominent militias in the PMF.
  • Harakat Hezbollah al Nujaba (HHN), or Movement of the Party of God’s Nobles (PMF Brigade 12) is an offshoot of AAH and KH. It is an Iraqi group that was originally formed in 2013 to support the Assad regime in Syria. In 2014, its mission expanded to fight ISIS. HHN leaders have publicly acknowledged Iran’s support. 
  • Kataib Sayyad al Shuhada (KSS), or The Masters of the Martyrs Brigade (PMF Brigade 14) was established in May 2013 to fight alongside the Assad regime in Syria. Similar to HHN, KSS expanded its operations to Iraq after the rise of the Islamic State in 2014. KSS has been supported and funded by the IRGC since its inception.
  • Kataib Jund al Imam (KJI), or The Imam's Soldiers' Brigades (PMF Brigade 6) was formed during the uprising against Saddam Hussein’s government in southern Iraq in 1991. It is affiliated with the pro-Iran “Islamic Movement in Iraq.” 
  • Saraya al Khorasan, or Khorosani Brigades (PMF Brigade 18) dates back to Iran-backed elements in the 1990s. It announced deployments to Syria starting in 2013 and later jointed the fight against ISIS.
  • Saraya al Jihad, or the Jihad Brigades (PMF Brigade 17) was established in 2014 soon after ISIS captured Mosul, Iraq’s second largest city. It is affiliated with the Jihad and Development Movement, a political party, and reportedly deployed to Syria to fight for the Assad regime.


Some of the information in this article was originally published on February 26, 2021.