¹ The seminal neorealist text is Waltz, Kenneth N., Theory of International Politics (Reading, Mass.: Addison-Wesley, 1979)Google Scholar. Debates over neorealism can be found in Keohane, Robert O., ed., Neorealism andIts Critics (New York: Columbia University Press, 1986)Google Scholar; Buzan, Barry et al. , The Logic of Anarchy: Neorealism to Structural Realism (New York: Columbia University Press, 1993)Google Scholar; and Baldwin, David A., ed., Neorealism and Neoliberalism: The Contemporary Debate (New York: Columbia University Press, 1993)Google Scholar. For the current state of the debate, see Powell, Robert, “Anarchy in International Relations Theory: The Neorealist-Neoliberal Debate,” International Organization 48 (Spring 1994)CrossRefGoogle Scholar; and Brown et al., an invaluable collection of important recent articles on realism from the journal International Security.

² Waltz (fn. 1), 71–72. See also the discussion of this point in Christensen, Thomas J. and Snyder, Jack, “Chain Gangs and Passed Bucks: Predicting Alliance Patterns in Multipolarity,” International Organization 44 (Spring 1990), 38 fn. 3CrossRefGoogle Scholar; Fareed Zakaria, “Realism and Domestic Politics,” in Brown et al.; and Schweller, Deadly Imbalances, 7–11. Robert Powell has questioned whether it is even useful or possible to speak of theories of international politics in isolation, since systemic theories must necessarily include nontrivial assumptions about states' preferences and behavior to begin with; see Powell (fn.l).

³ “Much is included in an analysis,” he writes; “little is included in a theory.” Waltz, Kenneth N., “International Politics Is Not Foreign Policy,” Security Studies 6 (Autumn 1996), 54–55CrossRefGoogle Scholar. Waltz was responding to the suggestion that scholars should devise and test theories of foreign policy emerging from his neorealist framework; see Elman, Colin, “Horses for Courses: Why Not Neorealist Theories of Foreign Policy?” Security Studies 6 (Autumn 1996)CrossRefGoogle Scholar.

⁴ Offensive and defensive realism are not only theories of foreign policy, but both schools commonly address foreign policy behavior and it is this aspect of them that will be treated here. The distinction between offensive/aggressive and defensive realism was first made by Snyder, Jack in Myths of Empire: Domestic Politics and International Ambition (Ithaca, N.Y.: Cornell University Press, 1991), 11–12Google Scholar, and has been widely adopted since then. See the following in Brown et al.: Sean M. Lynn-Jones and Steven E. Miller, “Preface”; Zakaria, “Realism and Domestic Politics”; and John Mearsheimer, “The False Promise of International Institutions.” See also Frankel, Benjamin, “The Reading List: Debating Realism,” Security Studies 5 (Autumn 1995), esp. 185—87Google Scholar; Fareed Zakaria, From Wealth to Power, Schweller, Randall L., “Neorealism's Status Quo Bias: What Security Dilemma?” Security Studies 5 (Spring 1996), esp. 114–15CrossRefGoogle Scholar; Desch, Michael C., “Why Realists Disagree about the Third World,” Security Studies 5 (Spring 1996), esp. 365CrossRefGoogle Scholar; Labs, Eric J., “Beyond Victory: Offensive Realism and the Expansion of War Aims,” Security Studies 6 (Summer 1997)CrossRefGoogle Scholar; and Walt, Stephen M., “International Relations: One World, Many Theories,” Foreign Policy 110 (Spring 1998), 37Google Scholar. Other authors make the same distinction but use idiosyncratic terminology. Thus Robert G. Kaufman substitutes “pessimistic structural” for “offensive” and “optimistic structural” for “defensive”; Stephen G. Brooks substitutes “neorealist” for “offensive” and “postclassical” for “defensive”; and Charles Glaser calls his variant “contingent” instead of “defensive” realism. Kaufman, See, “A Two-Level Interaction: Structure, Stable Liberal Democracy, and U.S. Grand Strategy,” Security Studies 3 (Summer 1994), 683ff.CrossRefGoogle Scholar; Brooks, “Dueling Realisms,” International Organization 51 (Summer 1997)Google Scholar; and Glaser, “Realists as Optimists: Cooperation as Self-Help,” in Brown et al. Finally, in an overview of recent realist theorizing, Joseph M. Grieco puts all neorealists into the defensive camp; see Grieco, “Realist International Theory and the Study of World Politics,” in Doyle, Michael W. and Ikenberry, G. John, eds., New Thinking in International Relations Theory (Boulder, Colo.: Westview Press, 1997), esp. 166–67Google Scholar.

⁵ Strassler, Robert B., ed., The Landmark Thucydides: A Comprehensive Guide to the Peloponnesian War (New York: Free Press, 1996), 5.89Google Scholar.

⁶ In their stress on intervening variables, constrained choice, and historical context, as in other ways, neoclassical realists have much in common with historical institutionalists in comparative politics, who study “intermediate-level institutions that mediate the effects of macro-level socioeconomic structures.” Neoclassical realists would agree that “this focus on how macrostructures … are magnified or mitigated by intermediate-level institutions allows us to explore the effects of such overarching structures on political outcomes, but avoid the structural determinism that often characterizes … [purely systemic] approaches.” Kathleen Thelen and Sven Steinmo, “Historical Institutionalism in Comparative Politics,” in Steinmo, Sven et al. , eds., Structuring Politics: HistoricalInstitutionalism in Comparative Analysis (Cambridge: Cambridge University Press, 1992), 11CrossRefGoogle Scholar.

⁷ For reasons of space and coherence this essay will focus on the general features of neoclassical realism as a theory of foreign policy rather than on the empirical contributions the various neoclassical realist authors have made to the literatures on their particular historical subjects.

⁸ For a brief history of Innenpolitik theorizing about foreign policy, see Zakaria, in Brown et al.; for a powerful restatement of the Innenpolitik tradition in modern social science terms, see Moravcsik, Andrew, “Taking Preferences Seriously: A Liberal Theory of International Politics,” International Organization 51 (Autumn 1997)CrossRefGoogle Scholar. On the concept of the democratic peace, see Brown, Michael E. et al. , eds., Debating the Democratic Peace (Cambridge: MIT Press, 1996)Google Scholar. Other notable recent examinations of Innenpolitik variables include Levy, Jack S., “Domestic Politics and War,” in Rotberg, Robert I. and Rabb, Theodore K., eds., The Origin and Prevention of Major Wars (New York: Cambridge University Press, 1988)Google Scholar; Rosecrance, Richard and Stein, Arthur A., eds., The Domestic Bases of Grand Strategy (Ithaca, N.Y.: Cornell University Press, 1993)Google Scholar; Skidmore, David and Hudson, Valerie M., eds., The Limits of State Autonomy: Societal Groups and Foreign Policy Formulation (Boulder, Colo.: Westview, 1993)Google Scholar; Hagan, Joe D., “Domestic Political Systems and War Proneness,” Mershon International Studies Review 38, supplement 2 (October 1994)CrossRefGoogle Scholar; idem, “Domestic Political Explanations in the Analysis of Foreign Policy,” in Neack, Laura et al. , eds., Foreign PolicyAnalysis: Continuity and Change in Its Second Generation (Englewood Cliffs, N.J.: Prentice Hall, 1995)Google Scholar; and Matthew Evangelista, “Domestic Structures and International Change,” in Doyle and Ikenberry (fn. 4).

⁹ Examples of offensive realist analysis include John Mearsheimer, “Back to the Future: Instability in Europe after the Cold War,” in Brown et al.; idem (fn. 4); and Labs (fn. 4).

¹⁰ Mearsheimer (fn. 4), 337 fn. 24.

¹¹ Prominent defensive realist authors include Stephen Van Evera, Stephen M. Walt, Jack Snyder, Barry Posen, and Charles L. Glaser; for citations to works in the defensive realist camp, see Zakaria (fn. 2), 476 fn. 34. For some of the reasons why defensive realists view systemic incentives as less Hobbesian than offensive realists do, see Brooks (fn. 4).

¹² Modern offense-defense theory is rooted in RobertJervis's presentation of the security dilemma; see Jervis, , “Cooperation under the Security Dilemma,” World Politics 30 (January 1978)CrossRefGoogle Scholar. Recent defensive realist works stressing the importance of offense-defense variables are Glaser (fn. 4);Hopf, Ted, “Polarity, the Offense-Defense Balance, and War,” American Political Science Review 85 (June 1991)CrossRefGoogle Scholar; Lynn-Jones, Sean M., “Offense-Defense Theory and Its Critics,” Security Studies 4 (Summer 1995)CrossRefGoogle Scholar; Evera, Stephen Van, “Offense, Defense, and the Causes of War,” International Security 22 (Spring 1998)Google Scholar; and Glaser, Charles L. and Kaufmann, Chaim, “What Is the Offense-Defense Balance and Can We Measure It?” International Security 22 (Spring 1998)Google Scholar; see also Levy, Jack S., “The Offensive/Defensive Balance of Military Technology: A Theoretical and Historical Analysis,” International Studies Quarterly 28 (1984)CrossRefGoogle Scholar. In addition to military technology, the offense-defense balance is sometimes held to incorporate judgments about whether power resources are cumulative and therefore offer a tempting target for potential aggressors; for an analysis of this question, see Liberman, Peter, Does Conquest Pay? (Princeton: Princeton University Press, 1996)Google Scholar.

¹³ Stephen Van Evera (fn. 12), for example, has recently argued that “a chief source of insecurity in Europe since medieval times has been [the] false belief that security was scarce.” In general, he claims, “States are seldom as insecure as they think they are … [the] exaggeration of insecurity, and the bellicose conduct it fosters, are prime causes of national insecurity and war” (pp. 42–43). Neoclassical realists question the point of constructing an elaborate systemic theory around the assumption that states are driven by a quest for security only then to argue that on security-related questions states suffer from false consciousness most of the time. The original neoclassical realist critique of defensive realism along these lines is Zakaria (fn. 2); see also Schweller (fn. 4).

¹⁴ Zakaria (fn. 2), 482.

¹⁵ Neoclassical realists acknowledge that in contrast to this “material” definition, the “relational” definition of power—in Robert Dahl's formulation, “A's ability to get B to do something it would not otherwise do”—has certain strengths, but they find it so fraught with theoretical and empirical difficulties as to be practically unusable. In addition to stressing the problems of empirically operationalizing a relational definition, they argue that employing such an approach makes it difficult to say much about the causal role of power factors relative to other potential independent variables. As Wohlforth writes: “If one defines power as control [over other actors, outcomes, or the international system as a whole], one must infer the relationship of power from outcomes. … Inferring the balance of power from outcomes and then using the balance of power to explain those outcomes appears to be a dubious analytical exercise.” For a clear discussion of these issues, see Wohlforth, 1–17. For arguments against the use of broad material definitions of power, see Dahl, Robert, “The Concept of Power,” Behavioral Science 2 (July 1957)Google Scholar; and Baldwin, David A., Paradoxes of Power (New York: Basil Blackwell, 1989)Google Scholar. See also Waltz (fn. 1), 191–92; and Robert O. Keohane, “Realism, Neorealism and the Study of World Politics,” in Keohane (fn. 1), 11.

¹⁶ One member of the school writes that “classical realists have written carelessly about ‘power-maximization,’ leaving unclear whether states expand for material resources or as a consequence of material resources. [Neoclassical realism] makes the latter assumption; increased resources give rise to greater ambitions. States are not resource-maximizers but influence-maximizers” (Zakaria, 19). Schweller considers this assumption too limiting and advocates incorporating a broader range of potential state preferences into neoclassical realist theorizing; see Deadly Imbalances, 18–26, 217 fn. 37; and idem (fn. 4).

¹⁷ See Wendt, Alexander, “Anarchy Is What States Make of It,” International Organization 46 (Spring 1992)CrossRefGoogle Scholar; and idem, “Constructing International Politics,” International Security 20 (Summer 1995)Google Scholar.

¹⁸ Michael Doyle has recently distinguished three separate theoretical strands within the classical realist tradition: Machiavelli's “fundamentalism,” which emphasizes the importance of individual ambition; Hobbes's “structuralism,” which emphasizes the importance of the international system; and Rousseau's “constitutionalism,” which emphasizes the importance of unit-level factors such as the nature and strength of state-society relations. All three strands, he argues, have their fins et origo in Thucydides' “complex” realism, which incorporates variables from each level of analysis; see Doyle, Michael W., Ways of War and Peace (New York: W. W. Norton, 1997)Google Scholar. For analysis of previous modern “classical” realists, see Smith, Michael Joseph, Realist Thoughtfrom Weber to Kissinger (Baton Rouge: Louisiana State University Press, 1986)Google Scholar.

¹⁹ Strassler (fn. 5), 1.23. For an excellent discussion ofThucydides as an international relations theorist, see Doyle (fn. 18), 49—92; other interesting recent treatments include Kauppi, Mark V., “Thucyd-ides: Character and Capabilities,” Security Studies 5 (Winter 1995)CrossRefGoogle Scholar; and Tellis, Ashley J., “Political Realism: The Long March to Scientific Theory,” Security Studies 5 (Winter 1995), 12–25CrossRefGoogle Scholar.

²⁰ Recent statecentric writings, particularly on foreign economic policy, represent a comparably rigorous and impressive literature; for a sampling of this work, see Ikenberry, G. John et al. , eds., The State andAmerican Foreign Economic Policy (Ithaca, N.Y.: Cornell University Press, 1988)Google Scholar; and Iken-berry, G. John, ed., American Foreign Policy: Theoretical Essays, 2d ed. (New York: Harper Collins, 1996)Google Scholar. Another approach, known as comparative foreign policy or foreign policy analysis, has generally produced little cumulation of knowledge or lasting impact; its recent offerings can be sampled in Hermann, Charles F. et al. , eds., New Directions in the Study ofForeign Policy (Winchester, Mass.: Unwin Hyman, 1987)Google Scholar; and Neack et al. (fn. 8).

²¹ Mandelbaum, Michael, The Fates ofNations: The Searchfor National Security in the Nineteenth and Twentieth Centuries (Cambridge: Cambridge University Press, 1988), 4CrossRefGoogle Scholar, 2.

²² Kennedy, Paul, The Rise and Fall ofthe GreatPowers (New York: Random House, 1987), xxiiGoogle Scholar, emphasis in original.

²³ Gilpin, Robert, War and Change in World Politics (Cambridge: Cambridge University Press, 1981), 94–95CrossRefGoogle Scholar, 22–23.

²⁴ Friedberg, Aaron L., The Weary Titan: Britain and the Experience of Relative Decline, 1895–1905 (Princeton: Princeton University Press, 1988)Google Scholar; and Leffler, Melvyn P., A Preponderance of Power: National Security, the Truman Administration, and the Cold War (Stanford, Calif.: Stanford University Press, 1992)Google Scholar.

²⁵ Friedberg (fn. 24), 8.

²⁶ Ibid., 295, 290–91.

²⁷ William Curti Wohlforth, “Realism and the End of the Cold War,” in Brown et al., 8. This article follows through on the argument of Wohlforth's book The Elusive Balance and should be read as its final chapter.

²⁸ Friedberg (fix. 24), 13.

²⁹ Keohane, “Theory of World Politics,” in Keohane (fn. 1), 167.

³⁰ Following Jervis's, RobertPerception andMisperception in International Politics (Princeton: Princeton Princeton University Press, 1976)Google Scholar, Wohlforth first dwelt on the implications of this point in “The Perception of Power: Russia in the Pre-1914 Balance,” World Politics 39 (April 1987).

³¹ Friedberg (fn. 24), 288.

³² The waters are further muddied, he argues, by a host of other problems: “Power cannot be tested; different elements of power possess different utilities at different times; the relation of perceived power to material resources can be capricious; the mechanics of power are surrounded by uncertainty; states possess different conversion ratios and comparative advantages; the perceived prestige hierarchy and the military distribution may not coincide for prolonged periods; states adopt asymmetrical strategies to maximize their positions and undercut rivals; signals get confused among allies, rivals, and domestic audiences” (pp. 306—7).

³³ In addition to his article “Realism and the End of the Cold War” (fn. 27), Wohlforth has teamed up with Schweller for a further neoclassical realist take on this subject; see Randall L. Schweller and William C. Wohlforth, “Power Test: Updating Realism in Response to the End of the Cold War,” Security Studies (forthcoming). On the difficulties in drawing clear theoretical lessons from these events, however, see Wohlforth, William C., “Reality Check Revising Theories of International Politics in Response to the End of the Cold War,” World Politics 50 (July 1998)CrossRefGoogle Scholar.

³⁴ Zakaria finds that American “statesmen's perceptions of national power shift[ed] suddenly, rather than incrementally, and [were] shaped more by crises and galvanizing events like wars than by statistical measures” (p. 11). Christensen argues that it was only the sudden awareness, in 1947, of the extent of British decline that shocked the Truman administration into recognizing the true distribution of power and triggered the shift toward active containment (pp. 32ff).

³⁵ Christensen, Thomas J., “Perceptions and Alliances in Europe, 1865–1940,” International Organization 51 (Winter 1997)CrossRefGoogle Scholar.

³⁶ As Zakaria points out, everyone knows Charles Tilly's mantra that “war made the state and the state made war”; it is just that heretofore the implications of the first clause have received far more attention than those of the second. See Zakaria, From Wealth to Power, 39—40; Tilly, “Reflections on the History of European State-Making,” in Tilly, Charles, ed., The Formation ofNational States in Western Europe (Princeton: Princeton University Press, 1975), 42Google Scholar; and Christensen, Useful Adversaries, 20ff. A similar stress on the role of state structure is a characteristic of some recent Innenpolitik theories as well, although the two schools differ over the nature and importance of this variable and the interpretation of many cases; for an overview of this work, see Evangelista (fn. 8). For pioneering examinations of the role of the state in the formation and implementation of foreign policy, see Katzenstein, Peter J., ed., Between Power and Plenty (Madison: University of Wisconsin Press, 1978)Google Scholar; Krasner, Stephen, Defending the National Interest (Princeton: Princeton University Press, 1978)Google Scholar; Ikenberry et al. (fn. 20); and Mastanduno, Michael et al. , “Toward a Realist Theory of State Action,” International Studies Quarterly 33 (December 1989)CrossRefGoogle Scholar.

³⁷ Cf. Waltz (fn. 1), 168.

³⁸ In some respects Christensen follows here in the footsteps of revisionist historians such as Richard M. Freeland; see Freeland, , The Truman Doctrine and the Origins ofMcCarthyism: Foreign Policy, Domestic Politics, and Internal Security, 1946–48 (New York: Schocken Books, 1974)Google Scholar. Unlike revisionist analyses of Truman's China policy, however, Christensen downplays the role of economic motives in American behavior and sees the Truman administration as using domestic anticommunism rather than creating it, and being in control of it rather than being controlled by it.

³⁹ Friedberg, Aaron L., “Ripe For Rivalry: Prospects for Peace in a Multipolar Asia,” International Security 18 (Winter 1993–1994), 11CrossRefGoogle Scholar. See also Schweller, Randall L., “Domestic Structure and Preventive War: Are Democracies More Pacific?” World Politics 44 (January 1992)CrossRefGoogle Scholar. For a neoclassical realist analysis of how domestic-level variables can be incorporated into realist theories, see Sterling-Folker, Jennifer, “Realist Environment, Liberal Process, and Domestic-Level Variables,” International Studies Quarterly 47 (1997)Google Scholar.

⁴⁰ For Scwheller's discussion of revisionism, see pp. 19–26; and idem, “Bandwagoning for Profit: Bringing the Revisionist State Back In,” in Brown et al.

⁴¹ Kennedy (fn. 22), xx.

⁴² Waltz, Kenneth N., Man, the State and War (New York: Columbia University Press, 1959), 238Google Scholar.

⁴³ On the use of “process tracing,” see George, Alexander L., “Case Studies and Theory Development: The Method of Structured, Focused Comparison,” in Lauren, Paul Gordon, ed., Diplomacy: New Approaches in History, Theory, and Policy (New York: Free Press, 1979)Google Scholar; and Alexander L. George and Timothy J. McKeown, “Case Studies and Theories of Organizational Decisionmaking,” in Advances in Information Processing in Organizations, vol. 2 (JAI Press, 1985). For an argument that Innenpolitik rather than systemic variables deserve to be the starting point for such a method, see Moravcsik (fn. 8), 541ff.

⁴⁴ Keohane (fn. 29), 187–88, emphasis in original.

⁴⁵ Waltz (fn. 1), 8–10.

⁴⁶ For the cloud/clock distinction and its implications, see Almond, Gabriel A. with Genco, Stephen, “Clouds, Clocks, and the Study of Politics,” in Almond, A Discipline Divided: Schools and Sects in Political Science (Newbury Park, Calif.: Sage, 1990)Google Scholar.

⁴⁷ Two recent examples of how psychological insights can successfully be brought into foreign policy analysis are Khong, Yuen Foong, Analogies at War: Korea, Munich, Dien Bien Phu, and the Vietnam Decisions of 1985 (Princeton: Princeton University Press, 1992)Google Scholar; and Mercer, Jonathan, Reputation and International Politics (Ithaca, N.Y.: Cornell University Press, 1996)Google Scholar; a useful survey of recent work in this area is Goldgeier, James M., “Psychology and Security,” Security Studies 6 (Summer 1997)CrossRefGoogle Scholar.

On ideas, see Sheri Berman, “Ideas, Norms, and Culture in Political Analysis” (Paper delivered at Workshop on Ideas and Culture in Political Analysis, Princeton University, May 1998). A recent sampler of foreign policy—related cultural analysis is Katzenstein, Peter, ed., The Culture ofNational Security: Norms andIdentity in World Politics (New York: Columbia University Press, 1996)Google Scholar.

⁴⁸ Rosen, , Societies and Military Power: India and Its Armies (Ithaca, N.Y.: Cornell University Press, 1996)Google Scholar; and Pollack, “The Influence of Arab Culture on Arab Military Effectiveness” (Ph.D. diss., MIT, 1996).

⁴⁹ See Robert W. Tucker, “Exemplar or Crusader? Reflections on America's Role,” National Interest, no. 5 (Fall 1986).

⁵⁰ The Adams quotation can be found in his “Address ofJuly 4,1821,” in LaFeber, Walter, e.d., John Quincy Adams and American Continental Empire (Chicago: Times Books, 1965), 45Google Scholar; the Wilson quotation can be found in his “Address Recommending the Declaration of a State of War,” April 2, 1917, President Wilsons Foreign Policy: Messages, Addresses, Papers, ed. James B. Scott (New York: Oxford University Press, 1918), 287.

⁵¹ Wohlforth (fn. 27), 19. This does not mean, of course, that easy answers to such questions are available. Paul Krugman was recently asked, “What are the great puzzles economists are trying to solve these days?” He replied, “The biggest question of all is still, ‘Why are some countries rich and some countries poor?’ Long ago, Bob Solow—the father of growth theory in economics—said that when it comes down to the question of why some countries do well over the long term and some do badly, you always end up in a blaze of amateur sociology. We're a little bit past that, but not much.” Wired, May 1998, 146.

⁵² Evangelista (fn. 4), 202; see also Harald Muller and Thomas Risse-Kappen, “From the Outside In and the Inside Out: International Relations, Domestic Politics, and Foreign Policy,” in Skidmore and Hudson (fn. 8), 29–32.

⁵³ The degree of optimism or pessimism about the future among Innenpolitikers and defensive realists, therefore, depends in part on how likely they think it is that at least one important power will succumb to a domestic pathology. For constrasting offensive and defensive realist views about future European security, see Mearsheimer, (fn. 9); Evera, Stephen Van, “Primed for Peace,” International Security 15 (Winter 1990–1991)Google Scholar; and Snyder, Jack, “Averting Anarchy in the New Europe,” International Security 15 (Winter 1990–1991)Google Scholar.

⁵⁴ Fareed Zakaria, “Speak Softly, Carry a Veiled Threat,” New York Times Magazine, February 18, 1996, 36.

⁵⁵ Friedberg, Aaron, “Warring States: Theoretical Models of Asia Pacific Security,” Harvard International Review 18 (Spring 1996), 13Google Scholar.

⁵⁶ Aristotle, , Nicomachean Ethics 1:3, in McKeon, Richard, ed., The Basic Works of Aristotle (New York: Random House, 1941), 936Google Scholar.