► Establishment and Progress of the Nuclear Consultative Group (NCG): Formed as part of the Washington Declaration in response to North Korea's nuclear threats, the NCG has held regular meetings to strengthen U.S.-ROK cooperation on nuclear deterrence, including joint planning, information sharing, and deployment of U.S. strategic assets.

► Key Achievements and Institutionalization: Significant achievements include the completion of the 'NCG Joint Guidelines,' enhancement of consultation and communication systems, and institutionalization of the NCG through a framework document. This has shifted NCG leadership to the defense departments of both countries.

► Future Directions and Strategic Importance: The 'U.S.-ROK Korean Peninsula Nuclear Deterrence and Nuclear Operations Guidelines,' approved at the NATO summit, formalize nuclear-conventional integration and emphasize joint operations. Future efforts will focus on maintaining regular NCG meetings, enhancing strategic deterrence capabilities, and developing flexible strategies to address evolving threats.

North Korea's relentless push to enhance its nuclear arsenal poses an escalating threat to South Korea, with recent developments raising the spectre of a potential preemptive use of nuclear weapons on the Korean Peninsula. Particularly concerning is the DPRK’s 2022 announcement of a new nuclear use doctrine, which raised the possibility of a preemptive, offensive nuclear strike against the ROK. In 2023, Kim Jong-un indicated plans to exponentially increase North Korea's stockpile of nuclear warheads, mentioning their deployment on strategic, intermediate, and tactical missile systems. Kim suggested that these nuclear weapons would not only serve as a deterrent but also play an active role in warfare.

South Koreans have taken North Korea’s nuclear threats seriously, and calls for new response measures have grown. In response, the U.S. and ROK governments held a summit on April 26 last year, resulting in the Washington Declaration. This landmark statement pledged to deter and respond to North Korea’s nuclear threats through strengthened extended deterrence and the establishment of the Nuclear Consultative Group (NCG). Since the Washington Declaration, the NCG has met regularly to discuss closer cooperation on extended deterrence. At the NATO summit on July 11 this year, the NCG’s accomplishments were highlighted in the "Joint Statement on U.S.-ROK Guidelines for Nuclear Deterrence and Nuclear Operations on the Korean Peninsula." This article explores the efforts of the NCG over the past year and the significance of these guidelines.

Results of NCG Meetings

The inaugural NCG meeting, led by the deputy heads of the U.S. and ROK National Security Councils, took place on July 18, 2023, at the Executive Office of the ROK President. The primary goal was to establish various working groups within the NCG and define their roles. A joint press report specified the meeting covered several topics: 1) Nuclear and strategic planning for responding to North Korean attacks; 2) Development of security and information-sharing processes; 3) Nuclear consultation and communication systems for crises and emergencies; 4) Cooperation on planning, operations, practice, simulation, training, and investment activities; 5) Joint planning on ROK conventional support for U.S. nuclear operations; and 6) Increasing the visibility of U.S. strategic assets. The discussions initiated the development of communication channels and security processes for sharing sensitive information between the U.S. and ROK. The meeting also aimed to expand the deployment of U.S. strategic assets around the Korean Peninsula to demonstrate the U.S. commitment to deterrence and reaffirm security guarantees to South Korea.

The second NCG meeting, held at the U.S. Department of Defense on December 15, 2023, continued these discussions. The discussion matter disclosed in the joint press release was consistent with that of the inaugural meeting. However, new terms like Conventional Nuclear Integration (CNI) emerged, suggesting integration of U.S. nuclear capabilities with South Korea's conventional forces for joint operations. The meeting emphasized that the NCG Joint Guidelines would be completed by the summer of 2024. During a correspondent briefing, the establishment of a communication system between the U.S. and South Korean leaders was disclosed, along with discussions on decision-making and political control related to nuclear operations.

On June 10, the third meeting took place at the South Korean National Defense Ministry, chaired by assistant deputy ministers from both countries' defense departments. The most significant achievement was completing the review of the NCG Joint Guidelines document, which provides principles and procedures for maintaining and enhancing the alliance's nuclear deterrence policy and posture. The meeting highlighted progress in various fields, such as sensitive information sharing, nuclear consultation procedures, nuclear-conventional integration, deployment of U.S. strategic assets, and strategic messaging. This progress significantly strengthened the alliance's posture and capabilities, laying a solid foundation for comprehensive extended deterrence cooperation between the U.S. and South Korea.

Efforts to institutionalize the NCG continued after the third meeting. On February 12, the South Korean Ministry of National Defense Policy Director and the U.S. Department of Defense Deputy Assistant Secretary for Space Policy signed the NCG Framework Document. This document institutionalizes the NCG efforts by defining goals, functions, and missions for its continuous and stable operation. Consequently, leadership of the NCG shifted from the National Security Councils of each country to their respective defense departments.

Detailed areas of development for extended deterrence include information sharing, consultation systems, joint planning, and joint execution. The NCG has advanced cooperation in these areas. Information sharing involves expanding the scope of sharing information on North Korea's nuclear threats and other militarily and strategically significant information. The U.S. and South Korea announced advancements in security and information-sharing procedures in a joint press release. The consultation system involves regularly holding high-level meetings of policymakers and working-level meetings to support them, and convening urgent meetings to identify response measures during crises. The establishment of a nuclear consultation and communication system for crisis situations was also disclosed. Joint planning means collaborating on nuclear deterrence and operations, particularly promoting the joint planning of non-nuclear support for U.S. nuclear operations and formulating response guidelines. Joint execution involves conducting various operational plans and combined exercises related to nuclear deterrence.

Enhancing the visibility of strategic assets and deployments delivers a deterrence message to potential adversaries and an assurance message to allies. This includes the port visit of a U.S. strategic nuclear submarine to Busan in July 2023 and the deployment of B-1B nuclear-capable strategic bombers to the Korean Peninsula in June 2024. Through the NCG meetings, the U.S. and South Korea have expanded cooperation in information sharing, consultation systems, joint planning, and execution related to nuclear operations, achieving significant results.

Meaning and Future Directions of the U.S.-ROK Korean Peninsula Nuclear Deterrence and Nuclear Operations Guidelines

On July 11, at the NATO summit, the U.S. and South Korean presidents approved and the NCG representatives signed the U.S.-ROK Korean Peninsula Nuclear Deterrence and Nuclear Operations Guidelines. This underscores the high status and significant policy and strategic influence of the document. It is the first to strongly address U.S. nuclear operations and responses to North Korean nuclear threats, formalizing U.S.-ROK nuclear-conventional integration.

The document emphasizes that U.S. nuclear assets will be tasked with missions on the Korean Peninsula in both peacetime and wartime to deter and respond to the advanced North Korean nuclear threat. This establishes a foundation for expanding practical nuclear response capabilities and posture, integrating U.S. nuclear forces with South Korea's advanced conventional forces to jointly share information, consult, plan, exercise, train, and operate nuclear-related activities on the Korean Peninsula.

As U.S.-ROK alliance cooperation expands from conventional force operations to include nuclear-conventional operations, the alliance's cooperation will be further elevated. This development will deliver a strong deterrent message against North Korean provocations while simultaneously enhancing military deterrence and response capabilities.

The U.S.-ROK Nuclear Consultative Group needs to continue its regular meetings as a permanent consultative body to strengthen cooperation in responding to North Korea's nuclear threats and develop flexible strategies to address new challenges. In conjunction with the establishment of South Korea's Strategic Command, the U.S.-ROK Strategic Commands need to enhance their strategic deterrence capabilities to contribute to peace and stability on the Korean Peninsula and in the region. Following the U.S.-ROK Korean Peninsula Nuclear Deterrence and Nuclear Operations Guidelines, it is necessary to systematically develop and implement specific action plans for joint planning and execution, exercises, and training on U.S.-ROK nuclear-conventional integration.