Any plausible position in the ethics of war and political violence in general will include the requirement of protection of civilians (non-combatants, common citizens) against lethal violence. This requirement is particularly prominent, and particularly strong, in just war theory. Some adherents of the theory see civilian immunity as absolute, not to be overridden in any circumstances whatsoever. Others allow that it may be overridden, but only in extremis. The latter position has been advanced by Michael Walzer under the heading of ''supreme emergency.'' In this paper, I look into some of the issues of interpretation and application of Walzer's ''supreme emergency'' view and some of the criticisms that have been levelled against it. I argue that Walzer's view is vague and unacceptable as it stands, but that the alternatives proposed by critics such as Brian Orend, C.A.J. Coady, and Stephen Nathanson are also unattractive. I go on to construct a position that is structurally similar to Walzer's, but more specific and much less permissive, which I term the ''moral disaster'' view. According to this view, deliberate killing of civilians is almost absolutely wrong.