The arrest of 14 members of Kataib Hezbollah late last month marked the boldest move yet by any Iraqi leader against the Iran-linked militias, which often operate in Iraq outside the law. Prime Minister Mustafa al-Kadhimi, who took office in May, has vowed to halt their attacks on foreign forces in the country, primarily U.S. troops.

But the response of the powerful militia to the June 26 raid underscores how challenging it will be for Kadhimi to recast the relationship between Iraq’s government and some of the country’s armed groups.

After gunmen in pickup trucks cruised Baghdad’s Green Zone demanding their comrades’ release, most were let go, then welcomed back to the group’s headquarters as heroes. Television stations linked to the militias live-streamed the men burning American flags and stamping on photographs of Kadhimi’s face.

“Does it become remembered as a humiliation of the militias, because the government had the temerity to arrest their guys like they’re a bunch of criminals, or does this get remembered as the day the militias drove around the international zone like they owned it and took their guys back from the government?” said Michael Knights, a senior fellow at the Washington Institute for Near East Policy. “That’s the question.”

Iraqi militias, including a few with close ties to Iran, played a crucial role in fighting the Islamic State group in Iraq starting in 2014, and many are now an official part of the state security apparatus, receiving salaries and weapons from the government.

But some of the groups, known as Popular Mobilization Forces (PMF), have resisted giving up their autonomy, and militants from Iran-backed militias have repeatedly launched rocket attacks on military and diplomatic locations housing U.S. personnel, prompting American frustration over the Iraqi government’s failure to rein the groups in.

Hundreds of Iraqi protesters, waving flags in support of Kataib Hezbollah and the Popular Mobilization Forces, demonstrated outside the U.S. Embassy in Baghdad in December 2019, breaching its outer wall. (Ahmad al-Rubaye/AFP/Getty Images)

As the U.S. and Iraqi governments prepare for fresh talks on the state of their relationship, the presence of U.S.-led coalition troops, and the security of those forces, are top of the agenda. Last year, a rocket attack that killed a U.S. contractor brought the United States and Iran to the brink of war on Iraqi soil.

Immediately after becoming prime minister, Kadhimi addressed militia leaders and fighters and warned of forces trying to harm the PMF’s relationship with the government, a veiled reference to attacks on U.S. forces by Iran-backed groups.

But the rocket attacks have not entirely stopped. So Kadhimi ordered the raid on Kataib Hezbollah, saying he had intelligence suggesting the group was preparing to strike the Green Zone.

Iraq’s special forces were notified early in the morning of an imminent mission. By the time their orders came down hours later, they had already guessed the target, according to a member of the special forces. “To be honest, we were excited. It’s about time someone moved against them,” he said, speaking on the condition of anonymity due to the sensitivity of the issue.

He said the special forces encountered no resistance. “This is a new era. They learned that attacks will have consequences,” he said.

Within hours, the armed militiamen responded, showcasing how easily they could enter the heavily guarded Green Zone and demanding the suspects’ release. All but one were let go, with the judge citing insufficient evidence.

But no rockets have landed near Western military or diplomatic facilities since then.

“It’s inconceivable that this would have happened nine months ago,” Knights said. “If this happens again, which I think it will, well, that’s the real test. Next time, [the militia will] be a lot more ready to hang onto their guys.”

Although Iran remains powerful in Iraq, Tehran’s allies have suffered various setbacks over the past nine months, Knights said, including the loss of Abu Mahdi al-Muhadis, who had led the PMF, in the U.S. drone strike in January that also killed top Iranian commander Gen. Qasem Soleimani. The militias were also blamed for violently repressing protests in Iraq’s mostly Shiite Muslim south.

Against this backdrop, Kadhimi made a gamble by raiding Kataib Hezbollah, challenging a group that is rarely confronted.

“They probably thought that Kadhimi was all talk, and this raid sent a different message out: that he is willing to back up his talk with these actions,” said Sajad Jiyad, a visiting fellow with the European Council on Foreign Relations. “There is rhetoric on both sides, but on the ground, I think that Kataib Hezbollah will be very careful going forward.”

In a statement Monday, Kataib Hezbollah’s secretary general emphasized its autonomy and rejected calls that the group hand over its weapons to the state, saying they should be used in the service of an Islamic resistance movement that includes other Iran-linked groups in Syria, Lebanon and further afield.

But this rhetoric aside, Jiyad stressed that the group partly derives its legitimacy with supporters from being part of the official Iraqi security forces.

“Remember, these are meant to be government forces led by the commander in chief. They cannot suddenly find themselves in complete opposition,” Jiyad said. “For now, I think that both sides are taking stock.”

Other PMF militias were more restrained in their reaction to the raid, suggesting they wanted to distance themselves from actions that might be seen as antagonistic to the Iraqi government.

“I think more established players see which direction the wind is blowing,” said Inna Rudolf, a research fellow at the International Center for the Study of Radicalization and Political Violence at King’s College London. Leading PMF figures have recently signaled their discomfort with the parallel authority some Iran-linked groups maintain, she said.

Western officials and analysts focused on Iraq say the coming months will be pivotal for Kadhimi’s efforts to curb the unruliest behavior of some militias.

There are few indications that Kadhimi is seeking to fundamentally reform the PMF or weaken its official position, which is governed by a law outlining the status of the militias and the remuneration its cadres receive. Many of the militias have a popular following and representatives in the parliament, and continue to play a security role across swaths of the country.

“The ball is in the militias’ court now, really,” said one Western diplomat, speaking on the condition of anonymity because he was not authorized to speak to the media. “If they choose to lob some more rockets, then Kadhimi really has to come through and back this up. Otherwise, the moment is gone. They’ve won.”

“Has he overplayed his hand?” asked another Western official. “Time will tell.”