To analyse an academic field of study in a particular era assumes two things: (1) that a particular era has properties that distinguish it clearly from predecessors and successors, and (2) that a field of study necessarily reflects or takes on a colouration of actual social conditions. Both assumptions are arguable, but the first is less contentious than the second. The Cold War was in many ways a distinct era, an era of anxiety caused by nuclear weapons, and an era in which diplomatic and military ideas, practices, and norms differed in significant ways from those prior to 1945 and after 1989. There were significant continuities, of course, but one would have little difficulty drawing compelling contrasts between the major characteristics of international politics in the 1920s and those of the 1950s.