Abstract
This thesis addresses the question, “What determinants best explain the differences between Japan’s and South Korea’s decision-making in response to the rise of China from 1992 to 2022?” It adopts a qualitative comparative case study and process-tracing methodology. The research draws on existing secondary literature, government documents, and 20 semi-structured interviews with current and former officials, advisors, academics, researchers, and journalists in Japan and South Korea.
The levels of cooperation with China of Japan and South Korea are the dependent variable. From 1992 to 2022, tensions with China increased for both states. However, Japan generally displayed a higher degree of tensions with China. Furthermore, the fluctuations in the South Korea-China relationship reflected the ebbs and flows of South Korea’s political landscape. There was no equivalent association between trends in Japan-China relations and Japan’s domestic politics.
This dissertation advances a neoclassical realist theoretical explanation in combining international and domestic factors to explain these differences. Geography created a different landscape for Japan and South Korea and is, therefore, an antecedent condition. Japan’s closer proximity to Taiwan means it would be more affected by a potential Taiwan contingency, contributing to its higher threat perception of China’s increasing assertiveness. South Korea is closer to North Korea, adding to its greater preoccupations with the inter-Korean conflict. This led South Korea to perceive China as having important leverage.
Material capabilities are the independent variable. Given Japan’s and South Korea’s economic and military growth rates, China’s rise has had a greater impact relative to Japan than to South Korea. This led Japan to have a higher threat perception of China’s rise. Additionally, South Korea’s higher level of economic dependence on China increased its perception of Chinese leverage. Together, geography and material capabilities illuminate the overarching trend of rising tensions in the Sino-Japanese relationship.
Domestic factors within Japan and South Korea explain why their relationships with China fluctuated differently. In line with neoclassical realism, they act as filters through which international variables are processed. First, there was a wider range of mainstream views on China policy in South Korea than in Japan. As a result, there was greater variation in the policy preferences of South Korea’s leaders. Second, power was distributed differently between the chief executive and the bureaucracy. South Korea’s presidents had more agency, domestically speaking, to implement their preferences. Japan’s prime ministers were more likely to face bureaucratic constraints. As a result, South Korea’s policy towards China fluctuated more with changes in its leadership, whereas there was more policy continuity across administrations in Japan.
These findings challenge structural realist explanations that neglect domestic politics, as well as cognitive arguments that disregard material capabilities. My research also challenges claims that factors such as US influence, proximity to Mainland China, or the legacy of the tributary system fully explain the differences between Japan’s and South Korea’s China policies. This thesis contributes to the broader understanding of how states navigate rising powers, offering insights into the complex interplay of international and domestic factors in foreign policy decision-making.