The rise of American Empire has coincided with appeals for a more humane war. During this period the campaign to abolish wars has transformed into to opposing war crimes, with fateful consequences. The ramifications of this shift became apparent in the post-9/11 era. By that time, the US military had embraced the agenda of humane war, driven both by the availability of precision weaponry and the need to protect its image. The battle shifted from the streets to the courtroom, where the tactics of the war on terror were litigated but its foundational assumptions went without serious challenge. These trends only accelerated during the Obama and Trump presidencies. This is the story of how America went off to fight and never came back, and how armed combat was transformed from an imperfect tool for resolving disputes into an integral component of the modern condition.