The killing of jihadism expert Hisham al-Hashemi has stirred fears Iraq is entering a dark and violent phase, as boiling tensions between pro-Iran factions and the government reach new heights.
Hashemi, 47, was gunned down outside his home in east Baghdad late Monday by masked assailants on motorcycles.
While the perpetrators remain on the run, experts say the death signals a dramatic turn for political violence brewing since mass protests erupted in October.
"Armed forces of various affiliations have killed protesters and others willing to publicly criticise the government and armed forces with impunity," said Belkis Wille of Human Rights Watch.
"But killing someone of his stature smacks of a country where some groups have become so emboldened by the complete impunity for serious abuses, that they can kill anyone they want to without paying a price," he said.
Over the course of years, Hashemi had developed a vast network encompassing top decision makers, former jihadists and rival political parties, often mediating among them.
His exceptional access had granted him a level of protection, those close to him said, but the balance started to tip in October.
His support for popular protests against a government seen as too close to Iran infuriated Tehran-backed factions in Iraq's Hashed al-Shaabi military network.
Hashemi skirted threats to mediate between protesters and senior government officials, even as activists were fatally shot outside their homes and dozens more abducted.
"The parameters changed starting in October. There was a new modus operandi, and a shift in the confrontation with pro-Iran factions," said Adel Bakawan, an Iraqi expert who knew Hashemi.
- 'Won't be the last' -
Other experts say the real turning point was in January, when a US strike on Baghdad killed Iranian General Qasem Soleimani and Hashed deputy head Abu Mahdi al-Muhandis.
Hardline factions within the Hashed, particularly those close to Iran like Kataeb Hezbollah, vowed revenge against both the US and its allies inside Iraq, whatever the cost.
As someone with close ties to foreign governments, Hashemi was seen as a potential target, and he left Baghdad for a few days in late January, he told AFP at the time.
"Hisham was aware that things had shifted," said Renad Mansour, a researcher at London-based Chatham House who worked with Hashemi for years.
"The killing of Abu Mahdi unleashed all of these groups that he had been trying to control and centralise. We're still feeling the shock waves," he said.
Hashed al-Shaabi itself published a statement mourning Hashemi's murder.
"We demand security forces follow up on this crime and catch the terrorist group that assassinated Hashemi," it said.
Within the network, Kataeb Hezbollah has accused then-spy chief Mustafa al-Kadhemi of complicity in the deadly strike and deeply opposed his rise to Iraq's premiership in May.
Hashemi had advised Kadhemi for years, a relationship that put the expert in "danger" when the former intelligence head became premier, those close to him said.
In recent weeks, Hashemi had been particularly critical of rogue elements of the Hashed and had received threats from at least two hardline factions, his associates said. His family, meanwhile, said he had been threatened by the Islamic State (IS) group.
"For the first time since 2003, there is a sacred alliance between the government and an influential group of intellectuals. Now, people who are both symbols of the protests and the government are being targeted," said Bakawan, who knew Hashemi personally.
"This may be the first prominent figure killed but it won't be the last. There are other names on this blacklist," he added.
- 'Suicidal mission' -
Kadhemi has pledged to hold Hashemi's killers to account, and swiftly sacked the police chief in the Baghdad district where the expert was killed.
But there is little hope for real accountability.
Less than two weeks ago, Kadhemi ordered the arrests of Kataeb Hezbollah fighters who were allegedly preparing a rocket attack on Baghdad's high-security Green Zone, home to the US embassy and other foreign missions.
But within days, all but one of those detained were released and their faction even pledged court action against Kadhemi.
Hashemi's killing appears to be a new challenge, said Iraqi politician Raed Fahmi.
"This is a political assassination that represents both the silencing of freedom of speech, and a challenge to the government, its prime minister and any reform plan," he said.
Other Iraqi activists told AFP they had long feared being targeted for speaking out against Iran-backed groups.
"This could have been any one of us. Our friends have already been notified to leave immediately," said Omar Mohammad, a historian who documented atrocities in Mosul under IS.
"If Kadhemi will not take a strong step, civil life in Iraq will vanish. But I'm afraid he won't do it. It's a suicidal mission," he told AFP.