Atomic Reactions: How and Why States Respond to Nuclear Proliferation

How do states react to countries pursuing nuclear weapons? And why? These questions are central to both academic and policy debates about the consequences of proliferation and speak directly to current challenges in nuclear politics. Despite the importance of these questions, the existing literature has largely avoided them, leaving gaps which this dissertation aims to fill. To answer the research questions, I introduce a series of eight conceptually distinct policies which states can adopt in reaction to the ambitions of a nuclear aspirant. Specifically, I distinguish between the use of force, balancing, economic statecraft, binding, abandonment, alignment, accommodation and assistance. This typology represents the palette of possible options available to policymakers in a state confronted by a nuclear aspirant. After laying out the typology, I next offer a theory for why states respond to nuclear aspirants in different ways. In brief, I argue that when developing a policy response to an aspirant, states prioritise international imperatives over domestic politics. The theory uses an analytic sequence of five variables: strategic rivalry, great power status, NPT membership, the existence of common enemies and domestic regime type to explain the policies states adopt in reaction to the spread of nuclear weapons. I test this theory by selecting a ‘representative sample’ of fourteen states and tracing how they each responded to India’s nuclear weapons programme between 1962 and 1998. Then, to assess the theory’s generalisability, I evaluate existing large-n tests of policy responses to nuclear aspirants and develop my own series of tests. The dissertation provides an answer to two central questions: what policies do states employ in reaction to countries developing nuclear weapons? And what factors determine states’ ultimate choice of policy? It presents a typology of foreign policy options and introduces a new theory with potential for wider application to other questions of comparative foreign policy. Finally, it presents a typology of foreign policy options, introduces a new theory and offers policy-relevant insight into how the international community is likely to react to future nuclear aspirants