Unlike the wars in Vietnam and Iraq, the U.S. invasion of Afghanistan in 2001 had near-unanimous public support. At first, the goals were straightforward and clear: defeat al-Qaeda and prevent a repeat of 9/11. Yet soon after the United States and its allies removed the Taliban from power, the mission veered off course, and the Bush, Obama, and Trump administrations never managed to regain momentum. Drawing upon a thousand interviews, three-time Pulitzer Prize finalist Craig Whitlock offers a thorough, nuanced look at what went wrong in Afghanistan.