25 Years After 9/11, War on Terror Legacy Shapes Iran Conflict

Twenty-five years after the September 11 attacks, the legacy of the "War on Terror" continues to shape U.S. foreign policy and domestic politics, with the ongoing conflict in Iran highlighting the enduring challenges of military interventionism. The 2001 attacks prompted a global response that evolved into prolonged wars in Afghanistan and Iraq, the rise and fall of ISIS, and now a direct military confrontation with Iran. The post-9/11 era began with the U.S. invasion of Afghanistan in October 2001 to dismantle al-Qaeda and remove the Taliban regime. The focus then shifted to Iraq in 2003, a war that faced massive global protests but lacked the support of traditional Western European allies like France and Germany. The Iraq invasion and its prolonged occupation are widely cited as having destabilized the region and contributed to the emergence of ISIS. The conflict with Iran represents the latest chapter. In February 2026, the U.S. and Israel launched a joint military operation against Iran's military and nuclear program, which resulted in the death of Supreme Leader Ali Khamenei.