Slim explores the problem of restraint in war by considering how civilians can be spared its ravages. With painful and poignant examples, he describes deliberate extermination, planned massacres, rape, and the famine and disease associated with war. This is more than a collection of horror stories, let alone a pacifist tract. Slim understands why wars sometimes must be fought and that attempts are often made to try to spare civilians unnecessary harm, and he grasps how the moral force of the civil-military distinction is soon undermined by the brutish logic of war, especially in these days of asymmetric war, when insurgents are constantly trying to draw regular forces into civilian areas. Lacking confidence in appeals to humanitarian law, he struggles to think of ways to assert the core principle that "even in war, one should kill as little as possible." He explores the possibility of appeals to self-interest, fairness, and mercy. Any attempt to carve out a humanitarian space in the midst of bitter conflicts faces tough challenges, but Slim's book is an important reminder of why it is vital to try.