This article takes issue with Jeff McMahan's well-known argument according to which, morally speaking, some civilians and POWs may be liable to wartime attack, and that in this respect the laws of armed conflict prohibiting such attacks diverge significantly from the deep morality of war. I reject McMahan's suggestion that at the deepest moral level it is sometimes justified to violate these legal protections of non-combatants and prisoners. I argue instead that the rules of war – moral as well as legal – are grounded in an age-old commitment to protect the defenseless and vulnerable, and can go only so deep without rendering them totally inapplicable to belligerent action. Consequently, I argue that there is little divergence between the laws of war and its deep morality. Ultimately, I suggest, this moral commitment to the defenseless supplies us with a significant point of convergence both between the law and morality of war, and between ad bellum and in bello considerations.