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YL Blog #47 – ROK-U.S.-Japan Defense Cooperation: Focusing on Strategic Communication Elements vis-à-vis the North Korean Nuclear Threat

Written By

  • Shin-ae Lee Research fellow in the Security Studies Group, Sasakawa Peace Foundation


North Korea under Kim Jong Un’s leadership has remarkably raised regional tension by improving its nuclear war capabilities and strengthening its negotiating leverage. Last year, Pyongyang had launched more missiles than in any other year and its new nuclear law declared its nuclear-weapon state status as “irreversible.” Moreover, since the beginning of this year, it has dauntlessly displayed upgraded missiles capabilities through a huge nighttime parade and incessant missile tests.

In response to impending threat, Republic of Korea (ROK), the United States (U.S.), and Japan, key stakeholders in the related crisis, have stepped up their joint endeavors to deal with Pyongyang’s provocation. These joint efforts aimed to improve interoperability to better defend North Korea’s nuclear threat. More importantly, it demonstrated the shared political will and capability to deter Pyongyang’s further provocations and ultimately persuade Pyongyang to give up its nuclear weapons. Hence, the trilateral defense cooperation signifies strategic communication elements, which essentially aim at “advancing national interests by using all Defence means of communication to influence the attitudes and behaviours of people.”

Ebbs and flows of trilateral defense cooperation

Despite being a significant tool of strategic communications, the trilateral defense cooperation remained an ad hoc and reactive approach with the ebbs and flows. As the new Kim Jong Un regime attempted to improve North Korea’s nuclear warfighting capabilities through nuclear and missile tests in 2016, the three countries held the first biennial missile defense exercise, Pacific Dragon, off the coast of Hawaii for the detection and tracking of ballistic targets. In addition, one year later, the first trilateral anti-submarine joint exercise was carried out in the waters near Jeju Island. The three sides clarified their commitment to constantly conduct the joint exercise for missile warning and anti-submarine warfare. They also made efforts to strengthen and stabilize the intelligence information sharing on North Korean issues between the U.S. and its allies. They signed the Trilateral Information Sharing Arrangement (TISA) in 2014 to facilitate the trilateral classified information sharing. In 2016, Seoul and Tokyo established the General Security of Military Information Agreement (GSOMIA) to enable the bilateral military intelligence sharing.

Although the three countries repeatedly delivered their willingness to continue the cooperation to deal with North Korea, these commitments were not being followed by action. The strained bilateral relationship since 2018 mainly due to the two sides’ unresolved historical disputes over Japanese colonial rule of the Korean Peninsula as well as the radar lock-on dispute inevitably halted the most trilateral security cooperation efforts. Although the trilateral joint statement pledged further trilateral defense cooperation including information sharing in June 2019, a few months later, Seoul and Tokyo had a bitter dispute over the termination of GSOMIA.

The trilateral cooperation got back the track in 2022 as the power of a conservative leadership returned in South Korea in the wake of conspicuous North Korea’s provocations. The three countries pledged in Phnom Penh to revitalize their defense cooperation and, in one voice, discouraged Pyongyang’s nuclear ambitions. Moreover, the trilateral exercises on ballistic missile defense and anti-submarine warfare was conducted for the first time in five years. Since then, the three parties have made significant progress in their trilateral cooperation in a relatively short time, notably in their efforts to operationalize real-time sharing of missile warning data and strengthen missile defense collaboration. They have consistently maintained trilateral communication channels, engaging national leaders, foreign ministers, defense ministers, and national security advisors. Above all, the recent Camp David Summit has elevated trilateral security ties to new heights. These accomplishments unequivocally showcase their collective commitment to addressing North Korean threats.

Key challenges

The reigniting of trilateral joint efforts sent a meaningful message to various stakeholders in the region and heightened the international expectations for their more active and consistent contribution to regional peace and security. However, the trilateral cooperation has a long way to go in terms of communicating credible and effective messages; messages which will support their goals.

The trilateral defense cooperation has been easily hobbled by the leadership change or political tensions between Seoul and Tokyo. The inconsistent cooperation got in the way of more effective coordination and interoperable capabilities to detect and defend against North Korean threats. Moreover, it enfeebled their deterrence efforts by revealing the discord within the coalition and made the adversary perceive the partnership less capable in countering North Korea’s provocations.

Indeed, it is critical to consistently implement multifaceted and coordinated activities, such as information-sharing, high-level policy consultation, joint exercises, and personnel exchanges to display the three countries’ strong determination and capabilities. However, that is not enough. The three countries should remind themselves that their communication is not only about sending messages but a two-way process with specific audiences in mind.

Often times, Pyongyang paid close attention to the trilateral movements, but reacted in an unintended way. Hence, the three countries need to refine their messages of deterrence and defense both via words and actions in a nuanced and careful manner to more effectively engage with Pyongyang. If the three-way cooperation were to announce concrete steps to confront North Korean provocations, and effectively translate words into actions, this would have a greater influence in deterring Pyongyang. If Pyongyang were to recognize that its provocations will inevitably undermine the regime’s own interests, it may think twice about needlessly agitating its neighbors. At the same time, the cooperation should put more emphasis on the unchanging deterrence- and defense-oriented nature of joint activities, which has no hostile intent toward Pyongyang. This would serve to counter Pyongyang’s justification of its escalating provocations, framing them as ‘corresponding measures’ against perceived national security threats.

Additionally, the three countries often forget that the South Korean and Japanese people should be the major audience of their defense cooperation. The public’s lack of awareness on the strategic significance of bilateral defense cooperation often results in unsupportive public attitude and has even, at times, rendered the trilateral defense cooperation vulnerable to political manipulation. The messages should elaborate more on the indispensable value of trilateral cooperation for their own country’s peace and prosperity and foster public awareness, which will ultimately stabilize the trilateral defense cooperation.

The situation regarding the North Korean threat has grown increasingly complex due to the escalating strategic rivalry between the US and China, coupled with the expanding Russian aggression, which has undermined unified regional efforts to deter further provocations by Pyongyang. China’s veto on an additional UN sanction on Pyongyang with Russia, has raised concerns over its manipulation of North Korean issue as a strategic asset. Amidst these challenges, the trilateral coalition has become more important than ever in influencing and shaping the desired behavior change of Pyongyang in a way to ensure regional security. The time has come for Seoul, Washington, and Tokyo to assess whether their messages to North Korea were received as intended and to adjust or recalibrate their messaging accordingly in light of a singular goal: a sustainable and capable cooperation for a peaceful resolution to the North Korea nuclear crisis.

Shin-ae Lee ([email protected]) received a Ph.D. in Public Policy from the University of Tokyo in 2022. She holds an MA in international studies from Seoul National University and a BA in political science from Ewha Womans University. She was previously a researcher at the Korea Institute for International Economic Policy and now serves as a research fellow in the Security Studies Group, Sasakawa Peace Foundation. She is also a Pacific Forum Next Generation Young Leader. She specializes in strategic communications of the second Abe administration, Japan’s foreign and security policy, and Korea-Japan relations.

Disclaimer: All opinions in this article are solely those of the author and do not represent any organization.