In a book full of insight and provocation, Chiu explores the ways that enemies at war can cooperate. These moments of collaboration between foes have included upholding standards of fairness in combat; establishing protections for noncombat-ants and prisoners, as required by the Geneva Conventions; and working together to bring fighting to an end. Such actions relate to the broader moral complexity of combat: for example, doctors at a field hospital may try but fail to save one of their own and then successfully treat the enemy solider responsible for their colleague’s death. And even as the killing proceeds—and despite rhetorical claims that victory depends on uncompromising ruthlessness—enemies can still set boundaries that preserve mutual respect and a shared sense of humanity. When unsure of a war’s purpose and strategic ration-ale, those on the frontlines make their own accommodations. In the trenches of World War I, soldiers often saw their own overzealous superior officers as more of a menace than the enemy.