U.S. Announces End to Combat Mission in Iraq, but Troops Will Not Leave

 The U.S. military on Thursday said it had completed its transition from a combat mission in Iraq to one meant to “advise, assist and enable” Iraqi forces that are battling the remnants of the Islamic State.

While the announcement signaled the latest shift in the mission in Iraq since the United States invaded 18 years ago, the move does not reduce the number of American forces in the country; rather, it will keep the same numbers of soldiers — roughly 2,500 — on the ground in support roles.

“We have come a long way since the coalition answered the call for help,” Maj. Gen. John W. Brennan Jr., the commander of the anti-ISIS task force in Iraq, said in a statement. “In this new phase, our transformative partnership with Iraq symbolizes the need for constant vigilance.

For the Iraqi government, the stated removal of combat troops was a political victory aimed at fending off pressure from Iranian-backed political parties and militias opposed to any presence of U.S. forces. It follows talks between President Biden and Mustafa al-Kadhimi, Iraq’s prime minister, in July, after which the president committed to removing all combat forces by the end of the year.

The move was seen by U.S. officials at the time as an effort to relieve pressure on Mr. al-Kadhimi, a U.S. ally who has had to balance ties with Iran to keep his position.

U.S. and Iraqi forces held a low-key ceremony in Baghdad on Thursday afternoon marking the transition to an “advise and assist” mission, an acknowledgment that American troops will largely continue to fulfill the same roles they have been since the territorial defeat of the Islamic State three years ago.

As part of the transition, the U.S. military said that it recently moved a logistics headquarters from a base in western al-Anbar province to Kuwait.

Thursday’s announcement comes just months after the withdrawal from Afghanistan following a 20-year occupation that Mr. Biden said the United States could no longer justify. But the administration has resisted a complete pullout from Iraq, where another war began after the Sept. 11 attacks, because it sees fending off the influence of Iran and the ongoing threat of the Islamic State as crucial to American strategic interests.

The U.S. military withdrew from Iraq in 2011 after failing to negotiate a status-of-forces agreement with the Iraqi government. Three years later, the Iraqi government asked it to return to help drive out the Islamic State, which conquered one-third of Iraq and large parts of Syria.

Whether Thursday’s announcement would be enough to appease Iranian-backed militia groups who have been calling for the complete withdrawal of American forces is still unclear.

One militia group now part of Iraqi government security forces said it had “no trust in any promise” made by the United States.

“If U.S. forces do not withdraw at the end of the year, it can be defined only as an occupation,” Harakat Hezbollah Al-Nujaba said in a statement. The militia is among the paramilitary forces mobilized in 2014 to fight the Islamic State and was later absorbed into Iraq’s official security forces and put on the public payroll.

“Targeting the U.S. occupation in Iraq is a great honor, and we support the factions that target it,” the group said.

The U.S. statement on Thursday noted that while coalition troops in Iraq do not have a combat role, they maintain the right to self-defense.

The United States has repeatedly blamed Iranian-backed militias for attacks on the American Embassy and U.S. bases within larger Iraqi bases. The militia groups say they are avenging the killing of Maj. Gen. Qassim Suleimani — Iran’s top security and intelligence commander and a senior Iraqi security commander — in an American drone strike in Baghdad last year.

After the strike, Iraq’s Parliament demanded the government expel U.S. forces — a motion that was nonbinding but sent a strong message to any politician who wanted to stay in power, including the prime minister.

Iranian-backed militia groups have retaliated using measures that include storming the outer walls of the U.S. Embassy compound in Baghdad’s heavily protected Green Zone. In recent weeks, militia members protesting the U.S. military presence have carried out a sit-in protest, setting up tents not far from one of the entrances to the Green Zone in an implicit threat against the embassy.

Tension in Iraq has been heightened by the disputed results of parliamentary elections in October. The country’s main Iranian-backed parties, some of them the political arms of militias, emerged with significantly fewer seats, while the movement of Muqtada al-Sadr, a Shiite cleric, gained seats. Mr. Sadr’s fighters fought against U.S. forces during the American occupation of Iraq, but he is now seen as a nationalist and a balancing force against more pro-Iran factions.

The groups that lost seats have called the election fraudulent, raising the prospect of violence if a federal court certifies the results as expected on Monday.

While violence by and among competing armed Shiite factions is the most immediate concern in Iraq, the Islamic State continues to pose a threat.

Major General Brennan in his comments on Thursday described the terrorist group as “down but not out.”

Although the Islamic State no longer holds territory, it maintains sleeper cells in Iraq and Syria. It has recently resurfaced in an area of Iraq claimed by both the federal government and Kurdish Iraqi forces.

While Iraqi forces have become increasingly proficient at fighting ISIS, they still rely on the U.S.-led coalition for intelligence help, operational planning and air support.