John J. Mearsheimer: an offensive realist between geopolitics and power Peter Toft Department of Political Science, University of Copenhagen, Østerfarimagsgade 5, DK 1019 Copenhagen K, Denmark. E-mail:
[email protected] With a number of controversial publications behind him and not least his book, The Tragedy of Great Power Politics, John J. Mearsheimer has firmly established himself as one of the leading contributors to the realist tradition in the study of international relations since Kenneth Waltz’s Theory of International Politics. Mearsheimer’s main innovation is his theory of ‘offensive realism’ that seeks to re-formulate Kenneth Waltz’s structural realist theory to explain from a struc- tural point of departure the sheer amount of international aggression, which may be hard to reconcile with Waltz’s more defensive realism. In this article, I focus on whether Mearsheimer succeeds in this endeavour. I argue that, despite certain weaknesses, Mearsheimer’s theoretical and empirical work represents an important addition to Waltz’s theory. Mearsheimer’s workis remarkablyclear and consistent and provides compelling answers to why, tragically, aggressive state strategies are a rational answer to life in the international system. Furthermore, Mearsheimer makes important additions to structural alliance theory and offers new important insights into the role of power and geography in world politics. Journal of International Relations and Development (2005) 8, 381–408. doi:10.1057/palgrave.jird.1800065 Keywords: great power politics; international security; John J. Mearsheimer; offensive realism; realism; security studies Introduction Dangerous security competition will inevitably re-emerge in post-Cold War Europe and Asia.1 International institutions cannot produce peace.