The Nuclear Balance Is What States Make of It

Does nuclear superiority offer states political or military benefits? And do those benefits accrue beyond acquiring a secure second-strike capability? International relations theory has long held that nuclear superiority does not confer significant advantages, a conclusion supported by much of the qualitative literature on bargaining and crisis interactions between nuclear-armed states. New work by scholars using statistical methods to analyze data on nuclear crises, interstate disputes, and compellent threats has sought to answer these questions, producing conflicting results. Despite the contributions of these recent works, this line of research has assumed that warhead counts are an appropriate measure of nuclear capabilities and that states possess accurate information about the material balance. Instead, states use multiple quantitative and qualitative characteristics to evaluate the nuclear balance, and they often have inaccurate or incomplete information about the size, composition, and configuration of other states' nuclear forces. Using new data, replications of two prominent recent works show that results are sensitive to how the nuclear balance is operationalized. Drawing on archival and interview data from the United States and the Soviet Union during the Cold War, findings show how states and leaders often understand and respond to the nuclear balance in inconsistent, asymmetric, and subjective ways.