By Junya Nishino —

Foreign Minister Fumio Kishida of Japan and Foreign Minister Yun Byung-se pose for a photo before their trilateral meeting with Secretary of State Rex Tillerson in Bonn, Germany on February 16, 2017. Source: U.S. Department of State, U.S. Government Work.
Ever since war broke out on the Korean Peninsula in 1950, Japan’s security ties with South Korea have been structured through the U.S.-Japan alliance. There has been a continued recognition over the decades of the importance of U.S. bases in Japan for effectively executing U.S. military operations during contingencies on the Korean Peninsula. Tokyo would also play a critical role in providing rear-area logistical support to U.S. forces in any conceivable conflict in Northeast Asia.
Security cooperation between Japan and the Republic of Korea (ROK) has therefore been encouraged by Washington rather than driven by Tokyo and Seoul themselves.
However, in recent decades, the growing threat of North Korea’s nuclear weapons and ballistic missile capabilities has pushed Japan to prepare more seriously for a crisis on the Korean Peninsula. As a result, Japan started to cultivate deeper bilateral security cooperation with Seoul in the early 1990s. Yet around the same time so-called history issues, like the Korean “comfort women,” related to the legacy of Japanese colonialism also began reemerging and derailing much needed progress in Japan-ROK defense ties.
For example, Japan and South Korea signed a memorandum on defense exchanges in 2009 and agreed to improve intelligence sharing and logistical support in 2011. Yet just an hour before the signing ceremony of a bilateral General Security of Military Information Agreement in June 2012, the Lee Myung-bak government in Seoul abruptly pulled out over flaring domestic criticism.
President Lee’s visit to the disputed Dokdo/Takeshima Islands in August 2012 and Prime Minister Shinzo Abe’s trip to Yasukuni Shrine in December 2013 further contributed to a vicious cycle of distrust.
Fortunately, the Japanese and South Korean governments agreed on a formula for solving the comfort women issue on December 28, 2015, which marked the 50th anniversary of the normalization of diplomatic relations between the two countries. Another significant step was the eventual signing of a bilateral information sharing agreement in November 2016.
Although Japan and the Republic of Korea have seen a rapid recovery in their bilateral relationship since 2016, they still face some tough challenges. The following five recommendations would be a good place to start moving forward with a bigger cooperation agenda:
First, Tokyo and Seoul should implement a “two-track approach” with regards to history issues. It is unrealistic to imagine that these thorny problems will disappear anytime soon. Nevertheless, since 2015 there have been growing signs that Japan and the Republic of Korea are looking to quarantine essential cooperation on security and economic matters from their history feuds. The Japanese and South Korean governments should make more joint efforts to steadily and fully implement the 2015 comfort women agreement, while also resisting any temptation to politicize the issue as a means of mobilizing domestic constituencies.
Second, the leaders of Japan and South Korea need to speak to their respective publics more enthusiastically about the importance of Japan-ROK cooperation, especially in the field of defense. Japan’s 2013 National Security Strategy made this clear when it stated that South Korea “is a neighboring country of the utmost geopolitical importance for the security of Japan.”
Third, bilateral policy consultations should be institutionalized and strengthened in order to encourage strategic dialogue. Resuming shuttle summit meetings on a regular basis should be a priority, as this step would prompt closer cooperation at the administrative level. One desirable formula is a “2+2” foreign and defense ministerial meeting, which could help define a common strategic vision, especially on the North Korean problem.
Fourth, Japan must also make efforts to work closely with South Korea to encourage Beijing to be a responsible partner and to respect international rules and norms. At the same time, differing perspectives on the rise of China have destabilized relations between Tokyo and Seoul and made it difficult for the two countries to cooperate more on various issues in East Asia. Tokyo should therefore take steps to alleviate Seoul’s concern about U.S.-China or Japan-China rivalry by supporting the China, Japan, and South Korea (CJK) trilateral cooperation secretariat (TCS) initiative.
Finally, security cooperation between Japan and South Korea should be expanded beyond traditional military issues to humanitarian assistance and disaster relief, peacekeeping operations, capacity building, and human security. An Acquisition and Cross-Servicing Agreement (ACSA) could be one useful tool. Nontraditional security cooperation is one area in which Japan and the Republic of Korea could engage other regional actors such as Australia and Southeast Asian countries.
In sum, Tokyo and Seoul can and should make greater efforts to maximize their opportunities for further bilateral and trilateral cooperation. The steps above can help to make such a vision into reality.
Dr. Junya Nishino is Professor of Political Science and International Relations at the Faculty of Law and Politics of Keio University. In 2017, he was a Visiting Scholar with the Japan Chair at the Center for Strategic and International Studies (CSIS) in Washington, D.C. Dr. Nishino’s essay is part of CSIS’s Strategic Japan Working Paper Series featuring Japanese scholars addressing pressing issues in Japanese foreign policy.