Abstract
Recent developments in U.S.-Soviet relations have prompted reassessments of the effects that nuclear weapons may have had on world politics. If there has been a “nuclear revolution,” both the meaning of that term and its precise implications for the behavior of states remain unclear. This article agrees with the realist argument that the discovery of nuclear weapons did not by itself fundamentally change the structure of the international system. However, it argues that the subsequent condition of nuclear deterrence, resulting from the widespread deployment of nuclear weapons and sophisticated delivery systems during the 1960s, does constitute a source of structural change. Under nuclear deterrence, the superpowers have acquired a new function—“joint custodianship” of the system—which differentiates their role from that of other states. This suggests that the international system has a new organizing principle that varies from the standard realist conception of anarchy. Structural change led to the rise of detente in the 1970s; but because the processes by which leaders in Washington and Moscow adjusted to structural change were not always parallel, this detente was limited in scope and could not be sustained. As processes of adjustment begin to converge, the modified structural approach proposed in this article predicts that superpower cooperation in a new detente of the 1990s will go beyond what was achieved in the 1970s and also beyond what would be consistent with standard realist arguments.