The long fraught relationship between Japan and the Republic of Korea has shown signs of improvement lately, which is particularly inspiring to American policymakers. After all, healthy Japan-ROK relations are key to the U.S.-Japan-ROK trilateral cooperation mechanism that Washington has worked to build over the years. It aims to create a fortress against China.
In recent years, the U.S. has both pressed and cajoled Japan and the ROK — both allies — to improve ties. Yet there was only limited progress until the pro-U.S. president of the ROK, Yoon Suk Yeol, decided to seek detente with Japan after taking office. High-level sources in Washington have openly claimed that the level of trilateral endeavors to contain China will be elevated considerably, thanks to improved ties between Tokyo and Seoul.
As to whether the momentum of improving Japan-ROK relations can be sustained over time, most observers believe the main obstacles are historical disputes over such issues as wartime “comfort women” and forced labor. High-level U.S. and ROK authorities have also stated repeatedly that Japan and the ROK should avoid being bothered by such “less significant” topics as history and territory and instead enhance cooperation, jointly cope with the significant changes in international and regional conditions and seek greater strategic interests, such as dealing with so-called China challenges. Following such logic, there seems to be a strong motive force for Japan-ROK cooperation, despite their being pestered by history.
However, if Japan-ROK cooperation is only constrained by historical ill feelings in the face of greater challenges and more important interests, it shouldn't be difficult for the two to put aside past disputes and collaborate. The reason Japan and the ROK won't be able to cooperate in the long run is rooted in their tremendous strategic divergence. Historical issues are only one manifestation of that divergence.
First, Japan and the ROK have different threat perceptions. As Stephen M. Walt pointed out in his balance of threat theory, a country will choose to check and balance the party that constitutes a greater threat to itself, not necessarily the more powerful party. Threat perception hinges on one's understanding of history and reality, which won't change easily because of any single incident. The U.S. and Japan see China as their main threat and challenge, so they actively try to rope in a third party to jointly strengthen the containment of China.
Yet the ROK is indecisive on the matter and has mainly followed a strategy of hedging between China and the United States. Although the present conservative ROK government is inclined to see China as a threat, that perception has yet to become a consensus between the ROK public and the elites. Based on their long experience of friendly co-existence and sincere cooperation, as well as the reality of the ROK benefiting tremendously from cooperation with China in the post-Cold War era, a considerable portion of the South Korean public and its elites don't take China as a major threat. Nor do they want to take sides in the strategic competition between China and the United States.
Conversely, Japan's image as a threat to the ROK is difficult to erase. This is not only because of the historical memories of multiple Japanese aggressions on the Korean Peninsula but because it reflects the reality that present-day Japan has yet to properly handle its right-wing forces and correct mistaken views of history. It has instead displayed a condescending attitude toward neighboring countries that had suffered from past atrocities. Ideas about past deeds tend to indicate policy propensities in the future. In this sense, South Koreans' vigilance on security cooperation with Japan and Japanese involvement in Peninsula affairs is not simple emotionalism. It has its own legitimacy.
Second, as the comprehensive strength gap between Japan and the ROK increasingly narrows, the competitive aspect of bilateral ties has become more prominent. During the Cold War, Japan was the Asian economic leader, and the ROK took Japan as an important support for domestic growth. So there was strong motivation for Japan-ROK cooperation. In recent years, the ROK has gradually caught up with Japan in its economy, science, technology and military capabilities. The ROK's economic dependence on Japan has dropped greatly, while it has become more dependent on China.
The ROK's GDP was only 10 percent of Japan's in 1995, but it reached 37 percent in 2021. Per capita nominal GDP in the ROK has also grown — from $6,516 in 1990 (26 percent of Japan's) to the more than $30,000 (about the same as Japan's), although per capita actual GDP still lags behind Japan. The rise of the ROK's electronics, auto-making, shipbuilding, and semi-conductor industries has put significant pressure on their Japanese counterparts. When it comes to military strength, the ROK has become comparable with Japan, ranking sixth and seventh in recent years globally.
The ROK wishes to play a larger role in regional and international affairs, which is not in Japan's interest. That Japan has imposed export controls on the ROK and repeatedly opposed its participation in the G7 and QUAD mechanisms was obviously driven by its fear of South Korea's rising international profile. Japan is also concerned that a strong, unified Korean Peninsula would challenge its advantageous status in East Asia.
Third, Japan and the ROK occupy different positions in America's alliance system. While the U.S. calls its alliances with Japan and the ROK, respectively, “cornerstone” and “linchpin,” it's nothing more than a game of words. Actually, Japan has always been at the core of America's Asian (even global) alliance regime. It is the second core — second only to the U.S. — in the U.S.-Japan-ROK, Indo-Pacific and QUAD multilateral mechanisms, which means the U.S.-ROK alliance is subordinate to the U.S.-Japan alliance in terms of strategic goals.
While both the United States and Japan are strategically focused on containing China, when the ROK joins the U.S.-Japan-ROK trilateral mechanism it has to first coordinate with U.S. and Japanese strategic needs, which will in turn distract from its own strategic focus — coping with the DPRK and domestic development — and significantly reduce its strategic autonomy.
While maneuvering the Japan-ROK relationship, the U.S. has mainly pressed Seoul to make unilateral concessions out of concern for the “big picture” and turned a blind eye to the revisionist and rightist turn in Japan, explicitly demonstrating different degrees of closeness with the two allies. The key is that the U.S. wants to rely on a right-leaning Japan as its foremost weapon and proxy in containing China, so it has to suppress legitimate ROK demands regarding Japan and try to push the ROK to the forefront of the U.S.-Japan confrontation with China.
Even the current pro-U.S. ROK government may find it difficult to accept such an arrangement. During a hearing in its Parliament on March 21, ROK Foreign Minister Park Jin, while refuting “humiliating diplomacy” allegations against him, argued that humiliation is the weak making compromises to the strong. Since the ROK has surpassed Japan in both state credibility and per capita purchasing power, it's no longer appropriate to define the matter in a weak nation/strong nation framework. Regardless whether the argument works or not, it reflects the fact that the ROK believes it is comparable to Japan in comprehensive strength and international influence.
To sum up, Japan and the ROK clearly diverge on mutual perceptions, strategic goals and national interests. The main motivation behind the current ROK initiative to improve ties with Japan has been external pressure from the U.S. and the conservative ROK government's obsession. But a consensus between the general public and elites remains absent. A Gallup survey in the ROK at the end of March found that President Yoon's approval rating had dropped to a low of 30 percent after his government moved to improve relations with Japan. The most frequent negative reasons were “diplomacy” and “Japan policies.”
As its national strength has grown in recent years, the ROK has proposed the ambitious goal of building itself into a global hub and has tried to exert greater international influence. These are natural aspirations. However, by attempting to elevate its own international status by consolidating the U.S.-ROK and U.S.-Japan-ROK alliances, it has actually eroded its own strategic autonomy by a great margin, with its own value and influence vanishing in the shadows of the U.S. and Japan.
As former ROK Minister of Unification Kim Hyo-seon once said, the essence of the U.S. using euphuisms to emphasize the need for consolidating the U.S.-ROK-Japan alliance and the Japan-ROK relationship subjugates the ROK to U.S. strategic deployments in the Indo-Pacific. The ROK has been reduced to the status of a subordinate partner. Therefore, the negative impact of an intensifying new cold war in the region — as the U.S. forcefully pushes for U.S.-Japan-ROK cooperation — should not be underestimated. One should not ignore the obvious differences and obstacles within the alliance, or the difficulty of moving forward.
