US-led coalition ends Iraq anti-ISIS mission as Iran-backed factions refuse to disarm

On Wednesday, the United States formally concluded a military mission in Iraq that had stretched across twelve years. The coalition, which first deployed to the country in 2014, had arrived to confront the Islamic State—a jihadist organization that had seized vast territories, executed civilians en masse, and enslaved thousands of women and children. By 2017, the group's grip on Iraq had been broken. By 2019, it was defeated in Syria as well. Yet American and allied forces remained, hunting remnants and maintaining a presence that would persist until this week's official end.

President Donald Trump announced the conclusion on social media as a decisive victory. "This Day is a victory for the United States, a victory for Iraq, and a decisive victory over ISIS," he wrote, framing the withdrawal as a choice to bring American troops home. The Iraqi government, led by Prime Minister Ali al-Zaidi, echoed the sentiment, with Zaidi declaring that "a new phase has begun, defined by Iraq's sovereignty, the strength of its institutions (and) the readiness of its forces." The formal agreement to wind down operations had been struck between Washington and Baghdad in 2024, and the actual withdrawal happened gradually, with American personnel eventually restricting themselves to the autonomous Kurdistan region in the north before departing entirely.

But the celebration masked a deeper anxiety. The coalition had not fought alone. Kurdish Peshmerga fighters had been essential to the campaign, as had powerful Iraqi armed factions—many of them backed and armed by Iran. These groups had been instrumental in defeating ISIS, yet they had never disarmed. As American troops left, those factions remained armed, organized, and politically influential. Hours after the US announced the mission's completion, supporters of Iran-backed groups gathered in a public square decorated with model drones to celebrate. A military spokesperson for Kataeb Hezbollah, one of the largest such factions, made clear that the withdrawal changed nothing about their weapons. The group said it had been in talks with the Iraqi government about "regulating" its arsenal but "have not yet received a response." Without an agreement, the spokesperson said, the factions were "not bound by any timeline" to surrender their weapons and retained "the right to directly respond to any American or Zionist violation of Iraq's sovereignty."

Prime Minister Zaidi had set September 30 as a deadline for disarmament, but withdrew it as negotiations continued. His government now hopes to broker a compromise, though the armed factions have made their terms clear: not only must foreign troops leave—which they have—but the United States must also end its political and economic involvement in Iraq. Kataeb Hezbollah framed the American departure as merely "a start towards achieving full sovereignty," but the group also issued a veiled threat to Zaidi's government itself. "A government that doesn't work for the good of its people will be brought down by all possible means," it said.

The stakes are high. These Iran-backed factions have spent years attacking American forces with drones and missiles, prompting retaliatory strikes that killed several commanders. During the broader Middle East conflict that erupted after US-Israeli strikes on Iran, Tehran and its allied groups intensified their operations in Iraq, targeting coalition troops in the Kurdistan region. Now, with those troops gone, the question is whether Zaidi's government can enforce disarmament or whether the armed factions will use their weapons to reshape Iraqi politics according to Tehran's interests. The formal end of the anti-ISIS mission does not resolve the underlying tension: a government trying to assert control over armed groups that refuse to acknowledge its authority.