In view of the overriding importance of the nuclear danger and the great relevance of psychology at certain points in any comprehensive discussion of how to cope with that danger, it seems to me that qualified psychologists—qualified by a basic knowledge of related disciplines—have both a right and an obligation to play an active part in that discussion, but not alone. Each of several other disciplines, political science, 20th century world history, Soviet studies, and the new discipline of “national security studies” (including nuclear hardware and strategy), has at least as much relation to such policy decisions as psychology. There are few, if any, nuclear policy decisions that follow directly from psychological considerations alone. The broad field of foreign and defense policy is like a great picture puzzle in which many psychologists hold one or more important pieces, but the pieces are meaningless until fitted in with others, and the others are much more numerous.