The Unipolar Illusion Revisited The Unipolar Illusion Christopher Layne Revisited The Coming End of the United States’ Unipolar Moment The key grand strate- gic issue confronting U.S. policymakers today is whether the United States can escape the same fate that has befallen the other great powers that have con- tended for hegemony since the origin of the modern international state system (circa 1500). Since the early 1990s, U.S. policymakers have embraced primacy and adopted an ambitious grand strategy of expanding the United States’ pre- ponderant power—notwithstanding the seemingly ironclad rule of modern in- ternational history that hegemons always provoke, and are defeated by, the counterhegemonic balancing of other great powers. U.S. primacy also has widespread support in the scholarly community. Primacist scholars claim that U.S. hard-power capabilities are so overwhelming that other states cannot real- istically hope to balance against the United States, nor do they have reason to because U.S. hegemony is benevolent.1 Like their policymaking counterparts, they believe that hegemony advances U.S. interests and that the United States can maintain its preeminence deep into the century. The United States’ hegemonic grand strategy has been challenged by Waltzian balance of power realists who believe that the days of U.S. primacy are numbered and that other states have good reason to fear unbalanced U.S. power.2 More recently, other scholars have argued that, albeit in nontraditional Christopher Layne is Associate Professor at the Bush School of Government and Public Service at Texas A & M University. He is author of The Peace of Illusions: American Grand Strategy from 1940 to the Present (Ithaca, N.Y.: Cornell University Press, 2006), on which this article is based in part, and (with Bradley A. Thayer) American Empire: A Debate (New York: Routledge, forthcoming). The author is grateful to Michael Desch and Gabriela Marin Thornton for reading drafts of this ar- ticle and offering very helpful comments. 1. For arguments that the United States can be a successful hegemon, see Joseph S. Nye Jr., The Par- adox of American Power: Why the World’s Only Superpower Can’t Go It Alone (New York: Oxford Uni- versity Press, 2002), especially chaps. 1, 5; Joseph S. Nye Jr., Bound to Lead: The Changing Nature of American Power (New York: Basic Books, 1990); Joseph S. Nye Jr., Soft Power: The Means to Success in World Politics (New York: PublicAffairs, 2004); Stephen M. Walt, Taming American Power: The Global Response to U.S. Primacy (New York: W.W. Norton, 2005); and William C. Wohlforth, “The Stability of a Unipolar World,” International Security, Vol. 24, No. 1 (Summer 1999), pp. 5–41. See also Ste- phen G. Brooks and William C. Wohlforth, “American Primacy in Perspective,” Foreign Affairs, Vol. 81, No. 4 (July/August 2002), pp. 20–33; Michael Mastanduno, “Preserving the Unipolar Moment: Realist Theories and U.S. Grand Strategy,” International Security, Vol. 21, No. 4 (Spring 1997), pp. 49–88; and G. John Ikenberry, “Institutions, Strategic Restraint, and the Persistence of Postwar Order,” International Security, Vol. 23, No. 3 (Winter 1998/99), pp. 43–78. 2. Following the Soviet Union’s demise, Kenneth N. Waltz and I predicted that unipolarity would quickly give way to multipolarity by stimulating the rise of new great powers. See Christopher International Security, Vol. 31, No. 2 (Fall 2006), pp. 7–41 © 2006 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology. 7 Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/isec.2006.31.2.7 by guest on 30 September 2021 International Security 31:2 8 forms, counterbalancing against the United States already is occurring. While many of these scholars favor primacy, they acknowledge that unless the United States wields its preponderant power with restraint, it could fall victim to a counterhegemonic backlash. One of the key questions in the scholarly debate is: What constitutes balanc- ing? Those who cling to a traditional deªnition of balancing, and those who ar- gue that there are new post–Cold War forms of balancing, disagree primarily on two issues: What are the instruments of a balancing strategy, and what mo- tivations drive states to engage in counterhegemonic balancing? Primacists deªne balancing in hard-power terms. Balancing is about using military power, alliances, or both to stop a hegemon. Primacists claim that states bal- ance against a hegemon because they are afraid of being conquered by it. This traditional deªnition of balancing has been challenged by scholars who argue that unipolarity has given rise to new forms of balancing. Unlike states engaged in hard balancing, states that employ these new forms of balancing do not believe that the hegemon poses an existential threat, though it may pose a more subtle kind of threat. Hence, they are searching for strategies to re- strain it peacefully and ameliorate the possibly harmful impact its preemi- nence may have on them. These new forms of balancing employ nonmilitary instruments of power. For example, “soft balancing” involves the use of diplo- macy, international institutions, and international law to constrain and delegit- imize the actions of a hegemonic United States.3 “Economic prebalancing” occupies a middle ground between soft balancing and hard balancing. States that pursue economic prebalancing are trying to avoid the risks of engaging in a premature arms buildup aimed at the United States by concentrating ªrst on closing the economic and technological gap between them and the United Layne, “The Unipolar Illusion: Why New Great Powers Will Rise,” International Security, Vol. 17, No. 4 (Spring 1993), pp. 5–51; and Waltz, “The Emerging Structure of International Politics,” Inter- national Security, Vol. 18, No. 2 (Fall 1994), pp. 44–79. Obviously, these predictions were wrong. I still believe, however, that the analytical case made to support the prediction that unipolarity would cause new great powers to emerge as counterweights was correct. Indeed, with China’s rise we gradually may be seeing the fulªllment of that prediction. For extended discussion, see Chris- topher Layne, The Peace of Illusions: American Grand Strategy from 1940 to the Present (Ithaca, N.Y.: Cornell University Press, 2006). 3. For discussions of soft balancing, see Walt, Taming American Power, pp. 126–132; Robert A. Pape, “Soft Balancing against the United States,” International Security, Vol. 30, No. 1 (Summer 2005), pp. 7–45; and T.V. Paul, “Soft Balancing in the Age of U.S. Primacy,” International Security, Vol. 30, No. 1 (Summer 2005), pp. 46–71. For counterarguments, see Keir A. Lieber and Gerard Alexander, “Waiting for Balancing: Why the World Is Not Pushing Back,” International Security, Vol. 30, No. 1 (Summer 2005), pp. 109–139; and Stephen G. Brooks and William C. Wohlforth, “Hard Times for Soft Balancing,” International Security, Vol. 30, No. 1 (Summer 2005), pp. 72–108. Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/isec.2006.31.2.7 by guest on 30 September 2021 The Unipolar Illusion Revisited 9 States. Successful economic prebalancing lays the foundation for hard balanc- ing in the future.4 Because soft balancing and economic prebalancing have been ably discussed and debated elsewhere, I do not discuss them further in this article.5 Instead, I contribute to the debate about what constitutes balancing by focusing on an- other new form of counterbalancing, which I call “leash-slipping.”6 States en- gaging in leash-slipping do not fear being attacked by the hegemon. Rather, they build up their military capabilities to maximize their ability to conduct an independent foreign policy. In this article I address three fundamental questions. First, is the United States insulated from challenge because of its alleged status as a nonthreaten- ing, or benevolent, hegemon? Second, since the Cold War’s end, have other states balanced against the United States? The answers to these two questions hold the key to answering a third: How long is U.S. hegemony likely to last? My central arguments are threefold. First, there are strong reasons to doubt the claim that other states view U.S. primacy as nonthreatening. Second, uni- polarity has not altered the fundamental dynamics of international politics: other states always have compelling incentives to offset the preponderant capabilities of the very powerful, even if the hegemon does not pose an exis- tential threat to them. Third, because the United States’ expansionist grand strategy reinforces other states’ perceptions that U.S. unipolar power is threat- ening, the United States must adopt a different grand strategy: an offshore bal- ancing strategy of self-restraint. This article unfolds as follows. First, I examine the reasons why Waltzian balance of power realists erred in predicting that the era of unipolarity would be only a brief transitional period between those of bipolarity and multi- polarity. Second, I deªne “hegemony” and describe the United States’ post– Cold War hegemonic grand strategy. Third, I critique arguments advanced by primacists to support their claim that U.S. hegemony will be long-lasting. Fourth, I demonstrate that in a unipolar world, the deªnition of “balancing” 4. China is following an economic prebalancing strategy. Beijing’s attempt to spin its great power emergence as a “peaceful rise” is strong evidence that Chinese leaders fear that the United States could act preventively against them before they can develop China’s full economic potential and convert it into hard military power. See Mark Brawley, “The Political Economy of Balance of Power Theory,” in T.V. Paul, James J. Wirtz, and Michel Fortmann, eds., Balance of Power: Theory and Practice in the Twenty-ªrst Century (Stanford, Calif.: Stanford University Press, 2004), pp. 110– 111. 5. For my views on these two forms of balancing, see Layne, The Peace of Illusions, chap.