The meeting between South Korean President Yoon Suk-yeol and US President Joe Biden to celebrate the 70th anniversary of the US-ROK relationship resulted in the issuance of the Washington Declaration, which focuses on South Korea’s extended deterrence options. The Declaration indicates that the United States pledged to strengthen extended deterrence dialogues and establish a new nuclear consultative group (NCG), while South Korea confirmed its nonproliferation commitments within the NPT framework.

It is noteworthy that the Declaration does not use the words “sharing” or “planning,” which are related to South Korea’s much-anticipated NATO-style deterrence mechanism and the Nuclear Planning Group (NPG), respectively. This omission was made to avoid any misunderstandings that might arise from the use of NATO’s nuclear cooperation terminology in Europe. It seems that the US aimed at preventing any misunderstandings and reducing tensions in South Korea regarding nuclear armament at the same time.

The Declaration has significant political value because it confirms what has already been agreed upon and specified at the defense ministerial level, providing momentum to implement existing agreements. Nonetheless, the South Korean government has stated that it anticipates a platform for active ROK participation in the decision-making process regarding the use of nuclear weapons, and it has praised the Declaration as an upgraded version of the Mutual Defense Treaty. It highlights that the Declaration specifies the use of nuclear weapons as a retaliatory option against North Korea for the first time in the alliance’s history.

However, South Korean government’s interpretation of the Declaration as an upgraded version of the Mutual Defense Treaty is questionable because it contradicts what the United States and South Korea have proclaimed and implemented for decades. The United States has provided extended deterrence, including a “nuclear umbrella,” to South Korea, which was officially stated in a jointly published document in 2006. Through the Security Consultative Meeting (SCM) the two allies developed a bilateral strategy for “tailored deterrence” in 2013 to maximize the effectiveness of US extended deterrence against North Korea. The US has reiterated its commitment to providing a full range of deterrence capabilities to South Korea, including the use of nuclear, conventional, missile defense, and advanced non-nuclear capabilities.

Because the allies reaffirmed previous agreements made at the defense ministerial level, the Declaration did not offer new information concerning the scope and level of a new consultative group beyond what has been discussed to this date. The NCG is expected to be similar to its predecessor, the Deterrence Strategy Committee (DSC). Through this consultation mechanism, the two allies have developed the Tailored Deterrence Strategy and Missile Response Strategy Implementation Guidelines. Besides, the NCG, like the DSC, is likely to be constrained in its ability to make substantial decisions due to its undersecretary-level discussion structure. In this light, the NCG could simply be a rebranded version of the current extended deterrence dialogue mechanism.

The Declaration commits to increase visibility of strategic assets on the Korean Peninsula, which have already been agreed upon by both countries. The Declaration commits the US to engage with South Korea on potential nuclear weapons use on the Korean Peninsula, but it does not specify the timetable or scope of such talks, leaving the amount and scope of US commitment to its discretion.

The Declaration highlights the need for increased coordination on South Korea’s conventional support to US nuclear operations in contingency situations. Again, this is a reaffirmation of the agreement reached at the 2022 SCM which confirmed the alliance’s commitment to cooperatively planning and implementing South Korea’s role in the combined deterrence posture and the expansion of the alliance’s capabilities, information sharing, consultation processes, and joint exercises. South Korea has expressed interest in conventional-nuclear integration and has been working towards this goal by integrating cyber, electromagnetic spectrum, and space domain capabilities. Thus, South Korea has prepared to hold more in-depth discussions about its role in contributing to the combined deterrence posture.

The Declaration emphasizes the allies’ commitment to enhancing their joint exercises and training efforts. To achieve this goal, the two allies declared to develop a new bilateral, interagency table-top exercise that is aimed at improving collaborative planning for nuclear contingencies. However, it was November 2022 when the US and South Korea agreed to conduct an annual table-top exercise of the extended deterrence system that simulates a North Korean nuclear attack scenario.

Moreover, the Extended Deterrence Strategic Coordination Group (EDSCG) has already pledged to improve information sharing, training, and exercises, including greater use of table-top simulations. The allies reaffirmed their commitment to continue discussing deterrence and response options through future table-top exercises in April. This effort is part of the comprehensive recommendations to strengthen extended deterrence that were addressed in the 2019 SCM.

The plans to further develop the combined deterrence posture on the Korean Peninsula were discussed through a joint study conducted by the allies during the Moon Jae-in administration. In the 2020 SCM joint communique, both sides reaffirmed their commitment to improving deterrence by following many of the policy suggestions from the extended deterrence joint study. To facilitate such cooperation, the two allies have established various consultative bodies, such as the Korea-US Integrated Defense Dialogue (KIDD), Security Policy Initiative (SPI), Deterrence Strategy Committee (DSC), and EDSCG.

The United States and South Korea have also formed the Counter-Missile Working Group (CMWG) and reactivated the Missile Defense Program Analysis Working Group (PAWG) to strengthen their cooperation on extended deterrence. Both parties have stated their commitment to continuing to work closely “through” these existing organizations to investigate methods to increase extended deterrence.

In order to assuage South Korean security concerns and counter calls in South Korea for an independent nuclear deterrent, the two allies cannot simply serve ‘old wine in a new bottle’. It is still unknown to which extent the new bilateral measures announced in the Declaration will provide additional value to the alliance, a question which warrants further examination.

About the Author

Jina Kim is Dean of Language and Diplomacy Division at Hankuk University of Foreign Studies. Previously, she was Chief of the North Korean Military Division at Korea Institute for Defense Analyses and Adjunct Professor at Yonsei Graduate School of International Studies. She is on multiple advisory boards for the Republic of Korea Ministry of National Defense, Ministry of Foreign Affairs, Joint Chiefs of Staff, Air Force, Seoul Metropolitan Government, and Peaceful Unification Advisory Council.

Image: Presidents Joe Biden and Yoon Suk-yeol make a toast during a state dinner at the White House in Washington, DC, Wednesday, 26 April 26 2023. (Official White House Photo by Cameron Smith)