Michael Walzer suggests that our common beliefs about individual responsibility and liability become largely irrelevant in the conduct of war. In conditions of war, everything is changed. Political realists have claimed that war eliminates morality; Walzer claims that war collectivizes it. I believe that conditions of war change nothing at all; they simply make it more difficult to ascertain relevant facts. This is not to say that the principles and laws that do or should govern the activity of war are identical to those governing relations among individuals. Just as domestic law cannot simply restate the principles of individual morality, because the declaration and enforcement of laws have effects that must be taken into account in the formulation of the law, so too the principles, conventions, and laws of war cannot simply restate the principles of individual or international morality. The rules of war have to accommodate our epistemic limitations and to be formulated with a regard for the ways in which their announcement is likely to affect people’s behavior. But they should otherwise reflect as closely as possible the..