Ole R. Holsti
Universities and professional associations usually are organized in ways that tend to separate scholars in adjoining disciplines and perhaps even to promote stereotypes of each other and their scholarly endeavors. The seemingly natural areas of scholarly convergence between diplomatic historians and political scientists who focus oninternational relations have been underexploited, but there are also some signs that this may be changing. These include recent essays suggesting ways in which the two disciplines can contribute to each other; a number of prizewinning dissertations, later turned into books, by political scientists that effectively combine political science theories and historical materials; collaborative efforts amongscholars in the two disciplines; interdisciplinary journals such as International Security that provide an outlet for historians and political scientists with common interests; and creation of a new section, “International History and Politics,” within the American Political Science Association.1
*The author has greatly benefited from helpful comments on earlier versions of this essay by PeterFeaver, Alexander George, Joseph Grieco, Michael Hogan, Kal Holsti, Bob Keohane, Timothy Lomperis, Roy Melbourne, James Rosenau, and Andrew Scott, and also from reading
K. J. Holsti, The Dividing Discipline: Hegemony and Diversity in International Theory (London, 1985).
This essay is an effort to contribute further to an exchange of ideas between the two disciplines by describing some ofthe theories, approaches, and "models" political scientists have used in their research on international relations during recent decades. A brief essay cannot do justice to the entire range of theoretical approaches that may be found in the current literature, but perhaps those described here, when combined with citations of some representative works, will provide diplomatic historians with auseful, if sketchy, map showing some of the more prominent landmarks in a neighboring discipline. The most enduring “great debate” among students and practitioners of international relations has pitted realism against various challengers. Because "classical realism" is the most venerable and persisting theory of international relations, it provides a good starting point and baseline for comparisonwith competing models. Robert Gilpin may have been engaging in hyperbole when he questioned whether our understanding of international relations has advanced significantly since Thucydides, but one must acknowledge that the latter's analysis of the Peloponnesian War includes concepts that are not foreign to contemporary students of balance-of-power politics.2 Following a discussion of classicalrealism, an examination of “modern realism” or “neorealism” will identify the continuities and differences between the two approaches. The essay then turns to several models that challenge one or more core premises of both classical and modern realism. The first three challengers focus on the system level: Global-Society/Complex-
constructivism. Subsequent sections discuss several “decision-making models, all of which share a skepticism about the adequacy of theories that focus on the structure of the international system while neglecting political processes within units that comprise the system. Several limitations should be stated at the outset. Each of the systemic and decisionmakingapproaches described below is a composite of several models; limitations of space have made it necessary to focus on the common denominators rather than on subtle differences among them. This discussion will pay little attention to the second “great debate,” centering mostly on methodological issues; for example, what Stanley Hoffmann called “the battle of the literates versus the numerates.”3 Efforts of...