To Pursue an Independent Nuclear Deterrent or Not? Japan’s and South Korea’s Nuclear Decision Making Models

Abstract

Concerns regarding potential nuclear proliferation activities of South Korea and Japan have increased following recent nuclear tests conducted by North Korea and following regional hegemonic actions by China. Both of these countries have bilateral security agreements with the United States, and are covered under the so-called “nuclear umbrella.” This paper poses the question: If these countries enjoy these security guarantees, what factors could contribute to their decision to pursue proliferation activities? This paper reviews some of the relevant literature on nuclear-decision making before proposing that perhaps these models are complementary rather than competing. For the purposes of South Korea and Japan, this paper asserts that there are two contributing factors that could cause either country to engage in proliferation activities: loss of confidence in the U.S. commitment to its extended deterrence obligations and regional security threats. Using case studies, this paper reviews the past proliferation activities by these two countries, and examines the mitigating factors that led to past decisions, and how such similar factors could impact future decisions. This paper uses historical analysis and investigation of contemporary security issues to examine the roles that extended deterrence and regional security have played and may play in the future, in each country’s interests in engaging in increased nuclear proliferation-sensitive activities.