BEIRUT -- The killing of a prominent researcher in Baghdad has sent shock waves through Iraq's government, underscoring the high stakes of its fight with powerful Iranian-backed militias and exposing the potential limits of the prime minister in taking them on.
Advisers to Prime Minister Mustafa al-Kadhimi have been taken aback that violence could reach so close to his inner circle. Hisham al-Hashimi, who specialized in security affairs, was a confidant to many of them, and his assassination July 6 drove home that few in Iraq are untouchable.
Although the assassin has yet to be identified publicly, Iraqi officials say he is linked to one of the Iranian-backed militias that Kadhimi has confronted since taking office in May.
Kadhimi has vowed to rein in militias operating outside the law, an effort pushed by the United States, whose 17-year military presence in Iraq has been violently targeted by some of these armed groups.
But it remains unclear how far Kadhimi will dare to go in taking them on over Hashimi's killing.
"He wants justice, but his hands are tied," said one adviser, speaking on condition of anonymity due to the sensitivity of the subject. "Launching a full-blown investigation into why this happened, well, that is simply too dangerous for any prime minister here."
Closed-circuit television footage of Hashimi's murder outside his house has been watched across Iraq, the grainy video a dark reminder of years when militias ruled the street. The gunman works quickly, shooting the 47-year-old researcher dead in the front seat of his car before slipping away into the night.
In Baghdad, Kadhimi's political associates have wondered aloud which one of them might be next. Some have disappeared from the airwaves. Others have left the city.
"Hisham's killing was a message, and everybody heard," said another of Kadhimi's aides. "They showed that no matter how well-connected you are, the militias can always reach you."
Hashimi became a victim of the escalating fight between the prime minister and the militias, part of a larger competition between the United States and Iran for influence in Iraq, say experts on Iraq.
Iraqi militias, including several with close ties to Iran, helped the Iraqi military and U.S.-led coalition battle the Islamic State, culminating in its defeat in Iraq in 2017. This earned the militias an official role in Iraq's security apparatus as part of the Popular Mobilization Forces, or PMF, with government-provided salaries and weapons.
Yet some of the Iran-aligned groups are accused of continuing to operate outside the law. They make money from extortion and smuggling and run a secret prison network. Some of the armed groups routinely launch rocket attacks on military and diplomatic facilities linked to the United States.
The prime minister has made a very public show of wanting to rein them in.
In an unusual show of force, he ordered the arrest of 14 members of Kataib Hezbollah on June 26, accusing them of planning to attack Baghdad's Green Zone, a sensitive diplomatic and political area near the center of the city, but the men were quickly released.
Experts said that this raid, rather than chastening the group, has emboldened the militias.
After a brief hiatus, rocket attacks resumed, this time claimed by shadowy new groups that Iraqi and U.S. security officials suspect to be fronts for well-known militias. The most recent rocket struck close to the U.S. Embassy as Iranian Foreign Minister Mohammad Javad Zarif was visiting the city.
Then, on Monday, a well-known German art curator, Hella Mewis, was snatched from the streets by armed men in a pickup. A government official, speaking on condition of anonymity due to the sensitivity of the situation, said the kidnappers were believed to have links to an Iran-backed militia. She was freed by security forces Friday in east Baghdad.
As one of Iraq's most respected analysts, Hashimi had once been well-connected with major figures inside the militias. But the U.S. drone strike in January that killed an Iranian general, Qasem Soleimani, and Iraqi militia leader Abu Mahdi al-Muhandis upended the militia scene, according to experts monitoring the groups, changing how they operated and who controlled them.
So when Hashimi began receiving death threats from their ranks in recent months, including from Kataib Hezbollah, he was at a loss how to respond.
"Whereas once he could call Muhandis or [others] to better understand and perhaps even mitigate the threats he faced, that option was no longer there," wrote Renad Mansour, a research fellow at Chatham House's Middle East and North Africa Program and a close friend of Hashimi. "All of his senior PMF contacts had gone into hiding and could not control increasingly rogue groups."
Muhandis' replacement, Abu Fadak al-Mohammedawi, took months to be named and does not have the same ability to forge a common position among the groups, militia sources and U.S. and Iraqi security officials say.
"And so it's harder and harder to track everyone," said one U.S. official, speaking on condition of anonymity due to the sensitivity of the situation. "We're seeing the impact of that now."