Force or Friendship? Explaining Great Power Nonproliferation Policy

Abstract

Why do great powers take such different approaches to the issue of nuclear proliferation? Why do states oppose nuclear proliferation more vigorously in some cases than in others? In short, what explains great power nonproliferation policy? To answer these questions, this article tests two competing theories of nonproliferation policy. The first, political relationship theory, suggests that states oppose nuclear proliferation to their enemies but are less concerned when friends acquire nuclear weapons. The second, power-projection theory, argues that states oppose the spread of nuclear weapons to states over which they have the ability to project military power because nuclear proliferation in those situations would constrain their military freedom of action. In contrast, states will be less likely to resist, and more likely to promote, nuclear proliferation to states against which they cannot use force. To test these hypotheses, this article uses evidence from great power nonproliferation policy from 1945 to 2000. While both theories find some support, the power-projection theory performs significantly better. The findings of this article have important implications for international relations theory and US nonproliferation policy.