| Japan-Korea (South Korea) relations showed enigmatic fluctuations during the Cold War. The persistent historical animosity has influenced their relations even after their diplomatic normalization in 1965. Accordingly, many analysts focus on the colonial legacies negatively affecting their relationship, stressing the abnormal, idiosyncratic, or non-Realist nature of the relationship, which without 'burden of history' would have been much more cooperative. Nevertheless, the strategic environment compelled Japan and South Korea to cooperate against the communist threats. As Realists would expect, Japan and South Korea also developed the alignment relationship in a bipolar world.; This mixture in Japan-Korea relations presents a puzzle: When is their relationship more cooperative and when more conflictful? This study, first, reconstructs Stephen Walt's balance-of-threat theory and Glenn Snyder's theory of alliance politics into a new single theory---Net Threat Theory---and presents a new balancing logic that demonstrates conventional balancing logic and public goods logic are not contradictory. Then, it applies the theory to the case of Japan-Korea relations, explaining their cooperation/frictions (dependent variable) as mostly a function of 'net threat' (independent variable), defined as "the balance between the common threat and the resources that are mustered against it." When applying the theory, this study assumes that in context of Japan-Korea-U.S. security triangle the net threat Japan and Korea perceives is mainly determined by the common threats and the credibility of the U.S. commitment.; It hypothesizes that when the net threat increases [decreases], Japan-Korea cooperative incentive increases [decreases]. The resultant cooperative incentive mostly determines the actual level of cooperation, but not always. Regardless of the level of net threat, there occurred various bilateral frictions due to the independent effects of conflicting interests. However, when the net threat increases, there is a tendency of those frictions being subdued earlier than when the net threat decreases or is unchanged. Historical animosity is not just a matter of irrational emotionalism, but is closely related to conflict of interests and thus to Realpolitik consideration.; This study argues Net Threat Theory is better than Walt's balance-of-threat theory or Cha's quasi-alliance model in Lakatosian sense. It better explains state behaviors in general and Japan-Korea cooperation/frictions in particular. |
