This article furnishes a philosophical background for the current debate about responsibility and culpability for war crimes by referring to ideas from three important just war thinkers: Augustine, Francisco de Vitoria, and Michael Walzer. It combines lessons from these three thinkers with perspectives on current problems in the ethics of war, distinguishes between legal culpability, moral culpability, and moral responsibility, and stresses that even lower-ranking soldiers must in many cases assume moral responsibility for their acts, even though they are part (...) of a military hierarchy and act under orders. The questions addressed in this article are arguably among the hardest and most muddled in military ethics and deserve close philosophical analysis and scrutiny. (shrink)