BAGHDAD — With American bombs raining down from the sky, Shiite militia fighters aligned with Iran battled Sunni extremists over the weekend, punching through their defenses to break the weekslong siege of Amerli, a cluster of farming villages whose Shiite residents faced possible slaughter New York Times reported.
The fight in northern Iraq appeared to be the first time American warplanes and militias backed by Iran had worked with a common purpose on a battlefield against militants from the Islamic State in Iraq and Syria, even though the Obama administration said there was no direct coordination with the militias.
Should such military actions continue, they could signal a dramatic shift for the United States and Iran, which have long vied for control in Iraq. They could also align the interests of the Americans with their longtime sworn enemies in the Shiite militias, whose fighters killed many United States soldiers during the long occupation of Iraq.
The latest expansion of American military operations reflects how seriously Iraq has deteriorated since the withdrawal of American forces in 2011. But any decision to support the Shiite militias, who have proven more adept than the American-trained Iraqi Army, would come with its own set of challenges.
The militants from the Islamic State in Iraq and Syria were able to storm into Iraq in recent months in part because Sunnis felt so disenfranchised by the Shiite-led government of former Prime Minister Nuri Kamal al-Maliki. If the United States is seen to be strengthening the hand of militias that terrorized Sunnis during the sectarian war of 2006 and 2007, the minority Sunnis might balk at participating in America’s long-term goal of a unity government.
Or, in a worst-case scenario, more Sunnis could align with ISIS fighters.
David Petraeus, a former top American military commander in Iraq who led the United States troop surge in 2007, months ago warned against such possibilities as the Obama administration, reeling from the fall of Iraq’s second largest city, Mosul, weighed military action against ISIS.
“This cannot be the United States being the air force for Shia militias or a Shia-on-Sunni Arab fight,” he said at a security conference in London in June. “It has to be a fight of all of Iraq against extremists, who do happen to be Sunni Arabs.”
The United States was careful to note on Sunday that it was working on Amerli with its allies: regular Iraqi Army units and Kurdish security forces, which the United States has been supporting with air power since President Obama authorized airstrikes several weeks ago.
“Any coordinating with the Shiite militias was not done by us — it would have been done by the ISF,” a senior administration official said on Sunday, referring to the Iraqi Security Forces. But it is well known that the Shiite militias have been fighting alongside the army in recent months as the threat from ISIS became clear.
A second administration official, meanwhile, said the United States is not working directly with Tehran. “We are working with the Iraqi government and with the Kurdish pesh merga in Iraq,” the official said. “That’s it.”
Security officials on Sunday said that Amerli, a town about 105 miles north of Baghdad whose estimated 15,000 residents are mostly Shiite Turkmen considered infidels by ISIS, was not fully liberated but that the combined forces had cleared several villages from the militants.
Last year ISIS exploited the chaos of the Syrian civil war to take control of large expanses of territory there, before sweeping into Iraq, its birthplace, as a greater force and erasing the border between the two countries. Its explosion onto a turbulent region has threatened the breakup of Iraq and forced a reluctant President Obama to re-engage more fully in the Middle East.
For overwhelmingly Shiite Iran, the rise of ISIS — and its aim of creating a Sunni caliphate in the region — was alarming because of the possible threat to Iran itself. The militants’ sudden successes also posed a more immediate threat of further destabilizing two countries — Iraq and Syria — that have been close to Tehran and helped it extend its power in the region.
In a reflection of the region’s increasingly tangled politics, the Obama administration is considering taking the fight against ISIS to Syria.
The United States and Iran have opposite goals there: Iran has been an important supporter of President Bashar al-Assad, while the United States has sought his ouster by supporting moderate rebels. But any American military action against ISIS in Syria could end up bolstering Mr. Assad — and furthering Iran’s regional agenda.
Iran’s president, Hassan Rouhani, at one point went so far as to suggest the United States and Iran might work together to stem the chaos in Iraq, but Iran’s supreme leader seemed unenthusiastic about the idea, and on Saturday, Mr. Rouhani said it would not be possible to cooperate in the fight against regional terror groups. It was unclear if his unexpectedly harsh criticism of the United States on Saturday was a sign of a change in attitude, or a political maneuver to either quiet domestic critics or to give Tehran wiggle room in negotiations over Iran’s nuclear program.
When President Obama first authorized airstrikes in Iraq several weeks ago, the justification was to protect American civilians in Erbil, the Kurdish capital, which was being threatened by ISIS fighters, and to support humanitarian aid drops on Mount Sinjar, where thousands of Yazidis, members of an ancient minority sect, had sought refuge from the advancing militants.
More recently, pressure had increased to help the besieged residents of Amerli, as officials worried that ISIS would carry out a mass killing of civilians. Besides the airstrikes, the United States also provided airdrops of food and water to the thousands of besieged civilians there.
The Obama administration has tried to avoid being seen as taking sides in a sectarian war, because the Shiite militias are especially feared by Iraq’s Sunnis.
But for the weekend at least, the realities on the ground appeared to override any concerns of effectively supporting the militias.
ISIS has been rampaging through Iraq, beheading prisoners, carrying out massacres of Shiites and expelling hundreds of thousands of residents. The Shiite militias have been accused of some recent abuses against Sunnis, but so far have avoided large-scale revenge killings.
Among the militias fighting for Amerli are Asaib Ahl al-Haq, considered the most fearsome of Iraq’s Shiite militias, and a group linked to the Shiite cleric Moktada al-Sadr, one of the Americans’ most unyielding enemies during the occupation. Those groups are supported by Iran.
Asaib, a militia that was a particularly fierce opponent of the United States as it was winding down its military role in Iraq, was said to have taken on the most prominent role in the fighting for Amerli, in Salahuddin Province.
“I would like to thank the jihadists from Asaib Ahl al-Haq, as they are sacrificing their lives to save Amerli,” said Mahdi Taqi, a member of the provincial council in Salahuddin.
Naeem al-Aboudi, the spokesman for Asaib, said, “today is a great happiness and victory for all Iraqis. Iraqi security forces, volunteers and resistance brigades have proved their ability to defeat ISIS.”
He played down the American role and said, “We don’t trust Americans at all. They had already let down the Iraqi Army.” He added, of the Americans, “We don’t need them.”
As night fell Sunday, the fighting was still raging in Qaryat Salam, a village to the north of Amerli. At a makeshift forward base, set up amid half-constructed homes and the hulk of a new soccer stadium, Kurdish pesh merga forces fired a barrage of artillery, mortars and rockets. A line of trucks roared into the area, their headlights smeared with mud to dull the brightness. An assortment of Kurdish fighters, Iraqi Army soldiers and Shiite militia members, who seemed to be working together in a highly coordinated way, passed by.
Several Iranian military advisers were also seen, according to a pesh merga fighter.
“We are cooperating with the pesh merga and other military forces,” said Abd Kadum al-Mousaw, a militia fighter. “From each force there is a commander who is a member of a higher committee that makes decisions.”
Pesh merga commanders said they had cleared about half of the village, but were facing stiff resistance from the militants, “who were fighting like madmen.”