To state the province and function of law in the control of war requires an understanding, in the broadest possible terms, of the nature of interstate conflict in the twentieth century. When such an understanding is reached, it will be seen that the traditional methodology of international law is inadequate for handling war-peace issues. While international lawyers should be faithful to the legal tradition of fact inquiry and judgment on the basis of legal norms, they should enlarge their perspective of international conflict and restructure their approach to the problem of war. The elaboration of this thesis is the subject of this note.