The Acquisition of Regional Ballistic Missile Defenses in the Shadow of Great Powers

The threat of nuclear proliferation has led to the rapid development, acquisition and deployment of ballistic missile defenses around the globe. Smaller powers located in the proximity of new or potential nuclear powers must decide on the right mix of offensive and defensive capability necessary to balance the threat. In terms of defense, they have a number of choices such as indigenous development, licensing for domestic production, procurement from third parties, and participation in multilateral defensive systems. This paper presents a theoretical framework that helps explain the decision by small states to deploy a ballistic missile defense system as well as the particular type of system chosen. The framework predicts that the level of threat of both the new or potential nuclear power and the regional great power will drive fears of the security dilemma, entrapment, and abandonment. The balance of these three fears will determine whether to deploy ballistic missile defenses as well as the type of defenses. Using a case study focusing on South Korea, the paper illustrates the evolution of defensive thinking among the political elite and public support for various defensive options.