Impeachment of Yoon Suk Yeol: Impact on US-Japan-ROK Cooperation
The recent impeachment of Yoon Suk Yeol has created many uncertainties not only about the fate of domestic political affairs in the Republic of Korea (ROK or South Korea), but also about the impact it may have on Seoul’s foreign and national security strategies. Amid political transitions in the United States and Japan as well, this rapid and unforeseen political crisis in South Korea adds greatly to concerns within and between the security communities of all three countries over its potential impact on the US-Japan-ROK trilateral security partnership as well as Japan-ROK bilateral relations which have been the crucial but most fragile link in the triangle. Reversal of the bilateral and trilateral cooperation efforts cultivated in recent years will create vulnerabilities against the ever-growing threats posed by China, North Korea, and Russia, which could destabilize the Indo-Pacific security environment. To avoid this, the US, Japan, and the ROK must work to ensure that trilateral security cooperation, as well as Seoul-Tokyo bilateral ties, are sustained and strengthened through these tumultuous times.
Effects of the Aftermath
From the viewpoint of Japan-ROK relations and the US-Japan-ROK trilateral security partnership, the greatest question has been who will lead the next administration in Seoul. While much remains uncertain, the populist Lee Jae Myung, leader of the progressive Democratic Party (DPK), has stood out. Not only does the DPK along with other liberal and progressive parties have the overwhelming majority in the National Assembly, but Lee has been the driving force against the policies of Yoon Suk Yeol and the ruling People’s Power Party.
However, while the DPK has gained momentum through Yoon’s martial law ordeal, there are serious questions about how it will direct the ROK’s foreign and national security policies, given that many of its members subscribe to nationalistic revisionism and hold strong biases against Japan and the US. The impeachment motion filed by the progressive opposition parties in early December claimed Yoon’s foreign and national security policies as having isolated the ROK in East Asia by antagonizing North Korea, China, and Russia while currying favor with Japan. While one may argue that this was merely symbolic rhetoric to deny every aspect of the Yoon administration, it nonetheless bolstered concerns in both Japan and the US about how a DPK oriented administration—if it comes into power—would work to revise the ROK’s initiatives with Japan and the trilateral framework with the US.
Problems are also compounded by the incoming Trump administration, which may de-prioritize the alliance commitments with Japan and the ROK, as well as trilateral cooperation. Consequently, the Trump administration may do little to promote, or even sustain, the trilateral framework and may be uninterested in the consequences of souring ties between Japan and the ROK.
The combination of the above raises grave concerns over how the efforts for trilateral coordination and cooperation over the past two years may be revised in the near- to mid-term future, given how much hinged on Yoon’s willingness to push forward despite deep-seated controversies in the ROK over closer relations with Japan. Even if the conservatives hold onto power, there are questions over how much political capital they have left to continue the path Yoon carved out in advancing Japan-ROK relations and US-Japan-ROK trilateral security cooperation.
Such concerns are not unfamiliar to many, where past attempts at institutionalizing trilateral cooperation either faded or fell short of making any significant impact—such as in the case of the Trilateral Coordination and Oversight Group, which was inaugurated in 1999 but dissolved in 2003. Even for the Defense Trilateral Talks and Japan-ROK bilateral defense dialogues, as well as other initiatives, their successes were highly dependent on the political climate among and within the states at the time, leading to inconsistencies in outcomes through political leadership changes, making coordination and cooperation unsustainable in the long run.
What is at Stake?
The “Spirit of Camp David” issued at the Biden-Kishida-Yoon summit in August 2023 and the initiatives undertaken by the US, Japan, and the ROK were about making the trilateral framework more resilient to domestic political affairs. The commitments are underpinned not simply by the shared threat perceptions of North Korea, but the three countries’ will to connect their Indo-Pacific security concerns and strategies. Even in Japan-ROK bilateral relations, the revival of “shuttle diplomacy”—regular, reciprocal summits—along with various exchanges have brought back much confidence between the governments and warmer interactions between the citizens of the two countries.
One only needs to look at the progress of the past two and a half years to understand what is at stake. At the strategic level, dialogues have taken place between the leaders, ministers, and chiefs of staff, agreeing on close coordination and institutionalization of initiatives. Greater developments have been evident at the operational level as well, with the operationalization of real-time information sharing regarding North Korean missile launches and trilateral defense drills, including the initiation of the “Freedom Edge” trilateral multi-domain exercises.
Although the aforementioned efforts are still young, they were nevertheless essential steps in filling the defense and deterrence gaps against growing threats posed by China, North Korea, and Russia. The problems are not simply about the continued military modernization and ever-increasing assertive operations of all three countries, but also the growing cooperation among them. Unwinding or even slowing down US-Japan-ROK trilateral defense efforts could potentially open up vulnerabilities against these adversarial threats, fueling tensions that could lead to further instability in the Indo-Pacific security environment.
Glimmer of Hope?
Although the US-Japan-ROK security framework hangs in the balance, not all is over, and there is still some hope on the horizon. Above all, the circumstances surrounding the Korean Peninsula have changed dramatically since 2019. On the down side, North Korea has resumed its missile launches with much greater frequency and pushed forward with its military modernization program, as well as issued its new policy toward the South. The implications of these developments go beyond the significant rise of tensions on the Korean Peninsula, but have created greater insecurity in the Indo-Pacific as a whole. Moreover, tensions remain high in the Taiwan Strait and combined with the current political crisis on the Korean Peninsula, there are understandable concerns about the risk of a simultaneous contingency in the region.
However, on the more positive side, the increasingly volatile regional security environment has served as a driver for both Japan and the ROK to recognize that their security interests are intertwined, making close trilateral coordination and cooperation with the US mutually beneficial and essential. Such perceptions are shared among the security communities in Japan and the ROK, with some notable improvements in public opinion in both countries as well.
The other important point is that the aforementioned systemization in trilateral coordination and cooperation in recent years has set strong institutional and procedural precedents for the future. Japan-ROK relations have been repeatedly taken one step forward and one step back. Numerous times, steps toward Japan-ROK security cooperation through dialogues, exercises, operations, and institutionalization were either halted or reversed due to political differences over historical and sovereignty issues or strategic diversions due to change of administrations in Seoul. Yet the initiatives undertaken in recent years have been two or three steps forward, making it difficult to completely reverse progress and providing a solid starting point that the states can come back to in the future.
Steps Needed Ahead
To sustain and further develop the trilateral partnership in a time when there are uncertainties concerning future leadership, the US, Japan, and the ROK must work together in the interim to prove that the framework is vital and beneficial for all parties at both national and regional security levels. Even if the political capital is limited in making further advancements, the three governments can still communicate and promote the benefits and feasibility of the trilateral framework, as well as highlight the agendas ahead.
Naturally, there are areas that need improvements going forward. At the strategic level, the three countries need to establish a formal trilateral consultative group to discuss and coordinate matters relating to their respective strategies, as well as extended deterrence. Such mechanisms will be vital not just to coordinate strategies and plans of the US, Japan, and the ROK, but to identify and work with gaps in expectations, visions, and capacity.
At the operational level, the three countries’ defense and law enforcement organs need to further coordinate their readiness for multi-domain operations, going beyond missile defense and anti-submarine warfare, and extending to areas such as intelligence, surveillance, and reconnaissance; remote island defense; cyber and electronic warfare; naval mine warfare; outer space; logistics; as well as humanitarian operations. To do this, however, the focus should not be just about formulating and practicing coordinated missions, but also on enhancing interoperability.
Conclusion
In South Korea, the US-Japan-ROK trilateral security framework is susceptible to becoming a domestic political football, and the partnership will be tested in the coming months. At the same time, there is no denying that the regional security environment has worsened because of the long-term revisionist ambitions of China, North Korea, and Russia. While diplomatic solutions are undoubtedly desirable, coordinated defense measures must continue to be pursued to ensure that both national and regional security is not compromised. In the end, it is not about who is preferred as South Korea’s next leader, but rather how they can pragmatically, productively, and realistically work with the US and Japan for regional security and stability while also repairing the state of domestic political affairs.