Much of the existing literature has accorded the Security Council with collective authority to confer legitimacy on actions involving the use of armed force. However, because of the veto, scholars have been able to point to relatively few instances in which the Charter has functioned thusly to legitimate or to restrain the actions of powerful states. This article provides an alternative conceptualization, treating the Charter as the basis of a broader system of international order in which legitimacy is conferred cumulatively, by both states within the Security Council and those outside of it, based on the extent of actions’ congruence with Charter rules that serve states’ shared interests. States’ expressions of acceptance confer legitimacy, while their expressions (and acts) of resistance withhold legitimacy, evoking prudential restraint from major powers attempting to signal their continuing commitment to the existing, postwar international order. The article applies this conceptualization to a case study of the 1962 Cuban missile crisis.