The last American forces are scheduled to leave their remaining bases in Iraq by Wednesday, September 30, formally ending more than two decades of U.S. military presence in the country. September 30 is the firm deadline for the coalition's military headquarters to shut down. The departure follows a two-phase withdrawal plan agreed in September 2024 during the presidency of Joe Biden. Phase one concluded in January of this year, when U.S. troops left the Ain al-Asad Air Base in western Anbar province and handed the site to the Iraqi army. The remaining American personnel, stationed at Erbil airport in northern Iraq, are set to depart in this final phase. The Trump administration is completing the pullout even as the United States wages an ongoing war against Iran. Iraqi Prime Minister Ali al-Zaidi has described September 30 as the "fixed and final" date, and Iraqi military officials say the country's security forces are ready to operate without foreign support. The announcement closes one of the longest and costliest chapters in American military history. The United States invaded Iraq in March 2003, toppling the government of Saddam Hussein. At the height of the counterinsurgency campaign in 2007, more than 170,000 American troops were deployed in the country. The last combat troops withdrew in December 2011, but U.S. forces returned less than three years later to help Iraqi forces defeat the Islamic State group. Coalition combat operations ended in 2021, after which a smaller American presence stayed on for training and counterterrorism work. Roughly 4,500 U.S. service members died in Iraq over the course of the war. Iran and its allies are treating the departure as a victory. Iran-backed groups in Iraq have spent years demanding the withdrawal of foreign troops and have repeatedly fired rockets and drones at American facilities. The United States killed the senior Iranian commander Qasem Soleimani in a drone strike at Baghdad airport in 2020. This year, as the United States and Iran remain at war, seven of the eighteen U.S. service members listed as killed in the conflict died in Iraq. Iraqi security analyst Jasim al-Bahadli told Reuters that Iran stands to gain strategically from the coalition's departure because it removes a military presence that for years acted as a counterweight to Tehran's influence. He said pro-Iranian militias would portray the exit as a triumph and try to turn that momentum into greater influence over security and political decisions. Not everyone is celebrating. Some Iraqi officials and tribal leaders worry the departure is coming too soon. A Sunni tribal leader in Fallujah told Reuters that while all Iraqis aspire to full sovereignty, he fears the coalition's exit will create a vacuum. Security officials also warn that the Islamic State group, which lost its self-declared caliphate nearly a decade ago but retains sleeper-cell networks, could take advantage of the gap. Kurdish commander Sirwan Barzani said there has been noticeable movement by Islamic State cells since the withdrawal deadline was announced, and Iraqi security forces reported a suspected cell preparing attacks timed to the pullout. The withdrawal has also reshaped U.S.-Iraqi logistics on the ground. Last week, the two countries signed a deal transferring the Diplomatic Support Centre at Baghdad International Airport, a facility attached to the U.S. embassy, to the Iraqi government. Iraqi officials say no foreign military bases will remain on Iraqi soil once the remaining coalition forces leave. Whether Iraq is ready to manage its own security without the coalition is now the central question. Iraqi commanders say their forces have improved and control the entire territory. American officials have long argued the opposite — that the coalition's training, intelligence, and drone support remain important. For Washington, the exit closes a costly era but opens new questions about leverage in a region where Iran's influence is deep and growing. For Baghdad, it is a milestone of sovereignty — and a test of whether that sovereignty can be secured by Iraqi forces alone.