Students and practitioners of international politics are at present in a strange predicament. Complex though their problems have been in the past, there was then at least some certainty about the “givens,” the basic structure and the basic phenomena of international relations. Today one is neither here nor there. On the one hand, for instance, one is assured—or at least tempted to accept assurance—that for all practical purposes a nuclear stalemate rules out major war as a major means of policy today and in the foreseeable future. On the other hand, one has an uncanny sense of the practicability of the unabated arms race, and a doubt whether reliance can be placed solely on the deterrent purpose of all this preparation. We are no longer sure about the functions of war and peace, nor do we know how to define the national interest and what its defense requires under present conditions. As a matter of fact, the meaning and function of the basic protective unit, the “sovereign” nation-state itself, have become doubtful.