On June 18, the Syrian regime accused the United States-led coalition of targeting one of its military positions next to the Iraqi border in the Euphrates river valley. It soon emerged that the airstrike, which the coalition denied carrying out, had killed and wounded dozens of members of an Iraqi Shi’ite militia called Kata’ib Hezbollah. Iraq’s Popular Mobilization Units (PMU), of which Kata’ib Hezbollah is one member, claimed twenty-two fighters had been killed and that the airstrike hit its forty-fifth and forty-sixth brigades. A U.S. official told CNN that Israel had carried out the strike. The airstrike in mid-June did not come in a vacuum and has broad strategic implications. The strike was the first of its kind on Iraqi Shia militias operating in Syria. It also symbolizes Washington and Jerusalem's continuing concern with Iranian-backed militias operating in Syria.
The fallout from the airstrike rocked Iraq throughout the week. On Tuesday and Wednesday Kata’ib Hezbollah fighters clashed with Iraqi security forces, even though they are ostensibly a paramilitary government force that is part of those security forces. The deaths also put the Fatah coalition party in Iraq in an awkward position. It is made up of PMU supporters and its leader, Hadi al-Amiri, runs the Badr organization—a militia similar to Kata'ib Hezbollah. Amiri is trying to form a government with Muqtada al-Sadr, but he also has to work with the United States in Iraq. This is because the American-led coalition is still training Iraqi forces and supporting its raids against Islamic State remnants. Furthermore, ISIS is still a serious threat in Iraq and has killed several members of the Shammar tribe on June 19 and has destabilized parts of Kirkuk province in recent months.
The airstrike also puts Iraq and the coalition in a bind and sheds light on the influence of Iranian-backed militias across Iraq and Syria. Israel’s Prime Minister Benjamin Netanyahu spoke to U.S. Secretary of State Mike Pompeo and Russian President Vladimir Putin forty-eight hours before the airstrike and warned that Israel would strike Iran throughout Syria. Israel has carried out more than one hundred airstrikes in Syria. Over the last year, these strikes have grown more elaborate as tensions rose amid Israel’s warning that Iran—and Shia militias that it backs—are entrenching themselves. Yet Iran shows no sign of leaving Syria, which it considers a close ally.
After Washington withdrew from the Iran deal, it began to express more full-throated support for Israel's view of the Iranian threat in Syria and also skepticism over the role of Iranian-backed militias in Iraq. Pompeo said in May that “in Iraq, Iran sponsored Shia militia groups and terrorists to infiltrate and undermine the Iraqi Security Forces and jeopardize Iraq’s sovereignty.” Former Secretary of State Rex Tillerson voiced similar concerns in October 2017 when he called for the militias to “go home.” In response, Iraqi Prime Minister Haider al-Abadi said the PMU fighters “should be encouraged because they will be the hope of the country and the region.”
Iraq presents these militias as an increasingly official paramilitary group affiliated with the Interior Ministry, based on a 2016 law passed in Baghdad. However, Washington sees them as descendants of terror groups who fought and killed Americans after 2004. Ostensibly the PMU grew out of a fatwa by Grand Ayatollah Ali al-Sistani to fight Islamic State in June 2014, when the extremists threatened Baghdad. But it was made up of existing groups. Kata'ib Hezbollah, the unit that the airstrike targeted in Syria, was designated a terror organization by the United States in 2009. “KH has ideological ties to Lebanese Hezbollah and may have received support from that group. KH gained notoriety in 2007 with attacks on U.S. and coalition forces,” the State Department noted. Kata’ib Hezbollah leader Abu Mahdi al-Muhandis not only fought against America but once served alongside the Islamic Revolutionary Guard Corps in Iran in the 1980s. Similarly, Qais Khazali, once a U.S. detainee at Camp Cropper, became a PMU leader in 2014 and his Asaib Ahl al-Haq militia is influential in Iraq. Moreover, both of these leaders have called on the United States to leave Iraq.
The PMU, and its involvement in Syria, put U.S. policy in Iraq in jeopardy. In December 2017 an inspector general report for the Department of Defense alleged that the PMU had obtained nine M1 Abrams Tanks that were supposed to be in the hands of the Iraqi army. Kata’ib Hezbollah was one of the units that were photographed with a U.S. tank during the war on ISIS.
As the conventional ground campaign against ISIS wrapped up in the fall of 2017, PMU units began crossing into Syria to aid the Syrian regime. For these groups, whose ideological roots are in the Islamic revolution in Iran, support of Syria's Bashar al-Assad Assad or Lebanese Hezbollah is natural. For instance, Qasem Soleimani, the IRGC Quds Force commander has been photographed in Syria with the Iraqi militias. Furthermore, PMU leaders also began traveling to the Lebanese border with Israel to stand with Hezbollah in late 2017 and early 2018.