The United States invaded Iraq in March 2003, saying that Saddam Hussein’s regime possessed weapons of mass destruction (WMD) and harboured terrorist groups. In 2011, then U.S. President Barack Obama announced America’s withdrawal, but its troops returned when the Islamic State captured huge swathes of territory in Iraq and Syria. On September 30, 2026, more than 23 years after the invasion, U.S. troops finally left Iraq, in the midst of another American war in the region. The war on Iraq has been one of the gravest strategic and humanitarian disasters of the 21st century. The WMD claim turned out to be false, if not an outright lie, while al-Qaeda built one of its most violent branches in post-war Iraq. The destruction of Saddam’s Ba’athist state and the abrupt rise of Shia parties widened social cleavages, triggering a deadly civil war, killing hundreds of thousands of Iraqis. The disastrous consequences of George W. Bush’s war did not end there. Al-Qaeda in Iraq transformed into the Islamic State by 2014 and spread terror across the region and beyond. The Popular Mobilisation Forces (PMFs, or Hashad al-Shabi), an umbrella of Iran-backed Shia militias, have since emerged as a state within the state.

Saddam’s Iraq, despite its hostile relations with Gulf monarchies, was a buffer between the Arab Gulf countries and Iran. When Saddam’s regime was toppled, Iran extended its influence across Iraq through Shia parties and militias. It is an irony that the U.S. is leaving Iraq at a time when it is trying to defeat Iran in a major regional war. But beneath the irony lies everything that went wrong with America’s regime-change wars, which destabilised parts of West Asia, gave rise to militias and jihadists and exposed the limits of American power in the region. When the U.S. and Israel began bombing Iran on February 28, Hashad joined the war. Since then, Iran and its allies have carried out at least 600 attacks on U.S. military and diplomatic facilities in Iraq, a stark reminder to Washington that maintaining troops there had become unsustainable. If in Afghanistan the U.S. exited after 20 years of war leaving the country in the hands of the same Taliban that it had toppled in 2001, in Iraq, America is leaving behind a war-ravaged country in the hands of a weak government and powerful militias backed by a resurgent Iran. Iran and its allies have vowed to push the U.S. out of West Asia. They may not have the wherewithal to achieve that goal, but they have managed to drive the U.S. out of Iraq.