The relations between the disciplines of history and political science have always been both close and, partly for that reason, contested. Political science grew in part out of history, which led its practitioners to be both deeply imbued with historical knowledge and to need to differentiate themselves from the study of history. Until about fifty years ago, the overlap between the disciplines was especially great in the international area, and the first issues of World Politics, the founding journal of international relations, had numerous articles by historians. For a variety of reasons, the gap widened, but in the sub-field of security studies contact never disappeared, in part because, as Stephen Schuker notes, scholars interested in this subject were marginalized in both disciplines. From my vantage point as a political scientist, it has seemed that the relationship has been less than fully balanced, with our interest in history not being fully reciprocated by our historian colleagues. I remember going to see Raymond Sontag (with whom, Schuker notes, Marc Trachtenberg studied) when I was a graduate student at Berkley to talk to him about my attempt to use history. He was too gracious to visibly wince at the idea of history being used in this way and did make clear that he was glad to see political scientists being interested in history, but it was also clear that he didn’t think we had much to contribute.