Michael Beckley’s Research and Policy Seminar Presentation

By Thomas Cavanna

CSS hosted Professor Michael Beckley as a speaker at its Research and Policy Seminar on October 15. Beckley, a professor at Tufts University, presented his new book project, entitled “Pax Americana: The Rise of U.S. Hegemony and the Decline of War.” This project investigates why global battle death rates per capita declined so steeply after 1945, and especially since 1991.

While this drop constitutes one of the most important international trends in the post-WWII era, leading scholars still disagree about its exact causes. Explanations range from the rise of new norms of non-violence to nuclear weapons, democracy, capitalism, or international organizations. Beckley recognizes their merits, but argues that these explanations remain unsatisfactory because they fail to reflect post-1945 variations in space and time and do not account for endogeneity.

Using a new dataset, Beckley addresses these gaps and advances the alternative argument that American hegemony, measured via proxies like defense pacts, is the true underlying factor that explains the global decline in battle death rates. Like past hegemons, the United States has promoted peace only in regions of strategic interest, and it has often indulged in violent and destabilizing policies elsewhere. However, Beckley’s global survey of the entire post-WWII era reveals that, on balance, America’s hegemony has played a pacifying role.

CSS seminar participants welcomed his work and offered a series of questions and comments on the contours of his project. Among the topics covered were the role of technology, the number of post-WWII interstate wars, the different proxies available to measure global violence, the role of Soviet hegemony in Central and Eastern Europe, the distinction between the United States and other hegemons, the agency of smaller states, the relationship between defense agreements and public goods, the impact of security agreements on peace, the role of U.S. institution building, the significance of potential outliers, the role of systemic factors in international relations, and the popularity of public goods. Beckley addressed all of these points extensively in a lively and fruitful discussion.

While this project is a long-term endeavor, its promises are already palpable. Armed with both robust quantitative data and in-depth historical narratives, it is set to contribute to several seminal debates in the field of international relations. Three contributions already stand out. First, it adds to our understanding of hegemony, bipolarity, multipolarity, and the impact of these various configurations on international stability. Second, it contributes to the grand strategic debate that pits deep engagement against restraint and offshore balancing, since their respective positions build on specific readings of the post-1945 decline in battle death rates. Finally, the project combines and transcends insights drawn from realism, liberalism, and constructivism to offer a new overarching analysis of America’s role in the world.