'Waltz, Mearsheimer and the post-Cold War world: The rise of America and the fall of structural realism'

Introduction

The end of the Cold War brought about a significant change in the international system and a new order emerged in which the United States was clearly revealed as the leading power.¹ The implications of this transformation for the relevance of structural realism or neorealism have generated a great deal of discussion in international relations (IR). Critics of structural realism maintain that this school of thought failed to predict or anticipate the end of the Cold War and the peaceful transition to a new era (see, for example, Gaddis, 1992; Kegley, 1993; Kratochwil, 1993; Lebow, 1994; Schroeder, 1994). Proponents of realism, however, claim that structural realism continues to shed a great deal of light on interstate relations, even in the post-Cold War period (see, for example, Wohlforth, 1994; Mearsheimer, 1995; Mastanduno, 1997; Schweller and Wohlforth, 2000; Waltz, 2000a; Hyde-Price, 2007).

Although much ink has been spilt on this issue, the debate has not moved any closer towards a settlement, as critics and proponents of realism tend to talk past each other. In order to avoid this problem, the present article challenges the leading and most comprehensive statements of the two main types of neorealism, Kenneth Waltz's defensive realism and John Mearsheimer's offensive realism, on their own terms, in order to evaluate their explanatory power in the post-Cold War era.² The research question that this study seeks to address is thus: How much explanatory power do Waltz's defensive realism and Mearsheimer's offensive realism have in the post-Cold War world if assessed on their own terms?

This is something that has not been done in the literature before (for the existing secondary literature on Waltz's defensive realism, see, for example, Keohane, 1986; Rosenberg, 2013; Quinn, 2013; for the existing secondary literature on Mearsheimer's offensive realism, see, for example, G. Snyder, 2002; Toft, 2005; Pashakhanlou, 2013). In doing so, this article also sheds new light on the consequences of unipolarity and hegemony for both Waltz's defensive realism and Mearsheimer's offensive realism. It is the first publication to demonstrate that both theories are inherently unequipped to account for international politics under these conditions.³ This study thus contributes to our understanding of central aspects of the most influential statements on defensive and offensive realism to...