Quasi alliance explanation for the fluctuating ROK-Japan relationship: analysing friction in 2019 and cohesion in 2023

ABSTRACT

The ROK-Japan relationship, characterized as a quasi alliance, has oscillated between moments of friction and cohesion. This study endeavours to pinpoint the explanatory variables responsible for these fluctuations and to articulate a coherent causal mechanism. Drawing upon alliance theories and the quasi alliance model, two hypotheses centred on external factors – common threats and common allies – are posite. In 2019, divergent threat perceptions between the ROK and Japan, coupled with doubts about the US's reliability, strained their quasi alliance. Yet, as the prospects for North Korea's denuclearization grew murky, both the ROK and Japan began to share heightened threat perceptions. Concurrently, the US's commitment and credibility were reestablished, bolstering the cohesion of the quasi-alliance. This study strengthens the quasi-alliance model both theoretically and empirically. Furthermore, the study's findings suggest the necessity for more direct and binding bilateral ties between the ROK and Japan to ensure greater stability in future relations.

KEYWORDS:

• ROK-Japan relationship
• quasi alliance
• tethering effect
• restraining effect
• trilateral cooperation
• balance of threat

Acknowledgement

The draft of this paper was presented at the 2023 Korean Association of International Studies (KAIS) Summer Conference on June 22, 2023. The author wishes to express appreciation to Professor Hanbeom Jeong of Korea National Defense University, participants of the graduate student session on Geopolitics and Security at the 2023 KAIS Summer Conference, and anonymous reviewers for their insightful comments and reviews.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 While the significance of China in the broader geopolitical context involving the ROK, the US, and Japan cannot be understated, this study is specifically focused on North Korea as a common threat, for several reasons. Firstly, the historical and ongoing tensions related to North Korea's nuclear capabilities and military posturing present a more immediate and direct threat to the security dynamics of the region, especially in the context of the ROK-Japan relationship. Secondly, the ROK's unique geopolitical position and its complex relationship with China necessitate a more cautious approach in any analysis that considers China as a potential threat. The ROK's strategy towards North Korea, heavily influenced by the need for regional stability and the potential for denuclearization, renders North Korea a more pertinent factor in this specific context. Lastly, this focused approach permits a more in-depth analysis of the ROK-Japan relationship without the additional complexities that the inclusion of China would introduce.

Additional information

Notes on contributors

Won-June Hwang

Won-June Hwang is a PhD student in the Department of Security Policy at the Korea National Defense University and also a Non-resident James A. Kelly Korea Fellow at the Pacific Forum, with his current research centering on alliance politics and international conflicts.