The American airstrike that killed a powerful Iranian general in Iraq on Friday also killed an Iraqi militia leader who was one of Iran’s top lieutenants in Iraq and a veteran of battles against the United States and the Islamic State.
The death of the militia leader, Abu Mahdi al-Muhandis, alone would have sent shock waves through Iraq, even if Maj. Gen. Qassim Suleimani, the intelligence chief who led Iran’s Quds Force, had not died with him.
As the deputy commander of a loose coalition of militias, Mr. al-Muhandis oversaw a disparate military force that arose to help Iraq defeat the Islamic State but has since become a power unto itself, its members operating with significant independence, often at the behest of Iran. Mr. al-Muhandis was also a founder of the individual militia that was attacked by American airstrikes on Sunday and that led the assault on the American Embassy in Baghdad this week.
He is still considered heroic by many Iraqis for his ability to corral Iraq’s bickering militias into an effective fighting force against the Islamic State. In the vacuum that followed Saddam Hussein’s fall, he created new networks to undermine the American occupation. And when Iran sought to embed itself in Iraqi life, it was Mr. al-Muhandis, fluent in Persian and close to General Suleimani, who served as its reliable right hand.
Mr. al-Muhandis advised the general, and both men preferred to operate from the shadows, even as their exploits earned them fame at home and enemies in the West. Born Jamal Jaafar Ibrahimi, he was better known by his nom de guerre and gained his greatest prominence leading the mostly Shiite militias that formed to fight the Islamic State in 2014.
Mr. al-Muhandis kept close ties with Iran throughout his life, including during the campaign that made him most popular at home: As Iraqi militias fought against the Islamic State, or ISIS, he publicly thanked Iran and General Suleimani for their support.
Iraq’s military condemned the airstrike that killed Mr. al-Muhandis, saying in a tweet that it mourned him as a hero.
Mr. al-Muhandis’s ties to Iran were well known. In 2009, he was identified as an adviser to General Suleimani by the United States Treasury Department, and accused of helping smuggle rockets, sniper rifles and other weapons from Iran to Iraq. American officials said he had also provided “logistical support for attacks” against coalition forces in Iraq and sent militia fighters to train in Iran.
Long before the American invasion of Iraq, he was accused of playing a role in the bombings of the French and American Embassies in Kuwait, in 1983, and the later attempt to assassinate Kuwait’s emir. In 2007, a Kuwaiti court sentenced him to death in absentia.
Much of Mr. al-Muhandis’s history remains murky, including his exact age: He would have been about 66 or 67 at the time of his death, according to the United States government, which has said he was born in 1953 in Basra, Iraq.
Mr. al-Muhandis fled Iraq with the rise of Saddam Hussein, who tried to crush the Islamic Dawa party, a Shiite group of which the future militia leader was a member.
Mr. al-Muhandis hoped to turn Iraq into a Shiite state similar to Iran after the Islamic Revolution of 1979. And he spent years in exile there, cultivating close ties with the Islamic Revolutionary Guards Corps, becoming fluent in Persian and keeping a home in Tehran.
He and many other Shiite leaders returned to Iraq in the aftermath of the American invasion in 2003, and Mr. al-Muhandis briefly served in Iraq’s Parliament before dropping out of public view.
He also helped found Kataib Hezbollah, a militia that targeted the United States during the Iraq war and was accused of training and equipping a network of anti-American groups. Kataib Hezbollah has continued to oppose the United States, and American officials blamed it for a rocket attack that killed an American contractor last week.
Kataib Hezbollah, which is separate from Hezbollah in Lebanon, denied responsibility for the attack.
After the attack, the United States launched airstrikes on five Kataib Hezbollah locations, killing at least 24 militia members. In response, pro-Iranian demonstrators, drawn largely from militias, swarmed the American Embassy compound in Baghdad, setting some outbuildings on fire.
The demonstrating militia members dispersed a day later, on orders from militia leaders, just days before Americans launched the drone attacked that killed Mr. al-Muhandis.
In a reflection of the chaos that has engulfed Iraq and the region, it was only five years after the Treasury Department put sanctions on Mr. al-Muhandis that he found himself effectively on the same side as the United States. The invasion of Iraq by the Islamic State from Syria gave his militia, Iran and the United States a common enemy.
Mr. al-Muhandis set about organizing mostly Shiite militias against ISIS, and the groups stepped in where Iraq’s military had collapsed and slowly wrested back territory.
About 30 militias have been loosely organized under an umbrella group, called the Popular Mobilization Forces, or P.M.F., that is technically overseen by Iraq’s government. But neither the Iraqi military nor any single faction has the authority to bring all the militias into consistent line: Each militia answers to its different leaders, who do not always agree with each other. Many, but not all, have ties to Iran.
The militias played a crucial role in demolishing ISIS’s self-declared caliphate, and Mr. al-Muhandis became “the most powerful single actor” among the militias, according to a November 2019 report by the International Institute for Strategic Studies. The report described him as “in essence an Iranian agent.”
After helping drive ISIS out of its territory in Iraq, many of the Iran-backed militias began trying to limit American activities in the country. Efforts by the current prime minister, Adel Abdul Mahdi, to curb the activities of Mr. al-Muhandis had failed, the report said.
American warnings to the Iraqi government about Mr. al-Muhandis went at least as far back as 2014, according to the The New Yorker. That year, the magazine said that Ryan Crocker, a former ambassador to Iraq, said that American officials told the prime minister at the time “that if Muhandis wanted to stay healthy he needed to stay in Iran.”