Mavrodes divides war into two classes, or separates war from other certain other international combats, in order to explore the moral significance of the distinction on the moral question of the intentional killing of noncombatants. The article first addresses the shortcoming of the arguments made by Elizabeth Ansombe, John Ford, and Paul Ramsey. It then explains the author’s distinction of war and why this distinction supplies the missing elements of previous treatments by other scholars. The author suggests that the immunity of noncombatants is not an independent moral rule but rather a part of a convention which sets up a morally desirable alternative to war and that moral conventions cannot be satisfactorily explained without reference to the convention.