North Korean Nuclear Deterrence Measures from the Perspective of Integrated Deterrence

Beom-cheol Shin

Senior Research Fellow

Introduction

The National Defense Strategy (NDS) released by the Biden administration in October 2022 presents the concept of integrated deterrence. According to the NDS, integrated deterrence entails working seamlessly across warfighting domains, regions, the spectrum of conflict, and all instruments of U.S. national power. It emphasizes the linkage between conventional and nuclear forces and seeks to deter aggression by utilizing the U.S.‘s network of allies and partners. 

The biggest threat we face is North Korea’s nuclear weapons. However, deterring the North Korean nuclear threat is not something that can be achieved overnight. Rather, it should be seen as part of the ongoing threat arising from the broader, lengthy process of unifying the Korean Peninsula. Of course, denuclearization negotiations, deterrence policies, and international cooperation should be carried out in parallel with this process. From this perspective, threat reduction and contingency preparations must proceed simultaneously. In other words, addressing the North Korean nuclear threat requires negotiations and deterrence building go hand in hand rather than being pursued separately, in addition to comprehensive and long-term planning. 

Although integrated deterrence presents a strategic perspective that utilizes South Korea's capabilities and links them with those of allied nations, it is a concept that can also be applied to North Korean nuclear deterrence in that it offers guidance for enhancing South Korea’s independent deterrence capabilities. Furthermore, as the deterrence strategy currently pursued by the United States, South Korea’s ally, it has various implications for South Korea. When South Korea moves beyond passively following U.S. strategic concepts and actively establishes an integrated deterrence framework tailored to its own needs, this will strengthen Korea’s capacity to deter North Korea’s nuclear threat. This brief will examine North Korean nuclear deterrence based on this principle.

Key Elements of Integrated Deterrence

The concept of integrated deterrence has gained prominence in recent years, but its core principle—–a government-wide approach–—has been evolving since the 19th century, when the concept of “total war” first emerged. The concept became more structured after the Vietnam war and evolved further in the 21st century alongside advancements in science and technology. Simultaneously, the integration of various military domains enabled enhanced command and control, which led to the development of the concept of Multi-Domain Operations (MDO) within the military domain. The concept of MDO was included in the 2018 NDS released by the Trump administration. Integrated deterrence can be understood as an expansion of this concept, broadening integration beyond the military domain to include the coordination of various national functions and international cooperation.

In presenting the concept of integrated deterrence, the United States emphasizes the integration of domains, theaters, and the spectrum of conflict, as well as an approach that utilizes all instruments of U.S. national power and the integration of allies and partners. This concept can be analyzed across the following three areas.

First is the strategic area. In this area, integrated deterrence is about establishing joint strategies or policies for deterrence among relevant countries. As the highest-level task, this involves fostering a shared threat perception and identifying shared policy priorities among nations with differing national interests. This type of cooperation often occurs among allies. However, there are significant obstacles to achieving complete strategic cooperation due to differing threat perceptions between countries. In the case of NATO in Europe, cooperation in strategic areas has been relatively smooth due to the consensus on the need to deter threats from Russia. However, the same cannot be said for the Indo-Pacific region. The region lacks a multilateral security agreement, and there is no consensus among countries in the region on issues related to China. While strategic cooperation among liberal democracies that share common values—–such as democracy, free trade, and human rights–—is on the rise, the task of sharing and aligning national strategies on specific issues, such as deterrence, remains a significant challenge. 

Second is the institutional area. The institutional area refers to the process by which cooperation becomes institutionalized through the deepening of trust during collaboration at the strategic level, as discussed earlier, or at the operational level, which will be examined later. In the military domain, this may involve the establishment of consultative bodies or standing organizations for information sharing and joint operations with relevant countries. Institutionalization is much more challenging in non-military domains. Unlike the military domain, which essentially focuses on deterrence issues, such as identifying threats and devising countermeasures, deterrence itself is not a main priority in domains like diplomacy and economics. For this reason, institutionalization regarding integrated deterrence in the non-military sector is much more difficult. Therefore, institutionalization is likely to be a challenging task in the process of establishing integrated deterrence.

Third is the tactical area. At the military level, integrated deterrence can begin with the implementation of Multi-Domain Operations (MDO). This involves achieving efficient command and control by integrating operations across land, sea, air, and space, as well as cyberspace. At the same time, operational integration must be achieved in a way that enables joint operations with allies and partners. At the non-military level, the key focus is on preventing adversaries from engaging in aggression through comprehensive cooperation between countries in areas such as information sharing, diplomacy, and collaboration between economic ministries. In practice, this represents the most fundamental stage of integrated deterrence, as it aligns with the objectives currently pursued in the defense policies of various countries and in their cooperation with allies.

Since the United States presented the concept of integrated deterrence in 2022, it has been integrating the functions of its military and strengthening cooperation with allies, under the leadership of the Department of Defense. The U.S. is working to integrate its nuclear forces, missile defense systems, and conventional forces while enhancing its command and control capabilities to facilitate Multi-Domain Operations (MDO). The U.S. is also strengthening cooperation with allies under the concept of integrated deterrence. Recently, the concept of integrated deterrence can be observed in the formation of consultative bodies and various joint exercises conducted within the Korea-U.S. alliance and trilateral security cooperation among Korea, the U.S., and Japan.

Strategic-Area Integrated Deterrence Measures to Counter North Korea’s Nuclear Threat 

Considering the growing nuclear threat from North Korea, enhancing deterrence is a critical task for the Yoon administration. Given the rapidly changing strategic environment on the Korean Peninsula, it is essential for South Korea to deliberate on how to design a strategy to deter North Korea’s nuclear threat at the strategic level. Strategic-level considerations for deterring North Korea’s nuclear threat ultimately converge on the three measures outlined below. Since flexibility is crucial, there is no need to focus on one single option. However, it is essential to assess changes in the environment in a level-headed manner to devise an optimal deterrence strategy.

□ Further Strengthening Korea-U.S. Extended Deterrence Cooperation

This measure aims to strengthen deterrence against North Korea’s nuclear threat by building on the Korea-U.S. extended deterrence framework and enhancing multi-domain cooperation based on the concept of integrated deterrence. At the military level, the focus is on developing extended deterrence to the operational level in a more substantive manner. Currently, South Korea and the United States are implementing extended deterrence at a level that does not involve the deployment of tactical nuclear weapons. This is because, when considering the U.S.'s existing strategic bombers, nuclear submarines, and various nuclear weapons systems, the need to deploy tactical nuclear weapons is deemed low. At the same time, the South Korean military is continuing its defense innovation efforts to transform into a science and technology-driven force, thereby strengthening the ROK’s advanced military capabilities. Additionally, the military is strengthening efforts to develop combined command and operational control capabilities in preparation for the transfer of wartime operational control (OPCON) from the United States to South Korea. This signifies South Korea’s commitment to further intensify these efforts and strengthen deterrence against North Korea’s nuclear threat.

At the diplomatic level, efforts to denuclearize North Korea and deter the North Korean nuclear threat should be integrated. South Korea and the United States should take a more systematic approach in leading international cooperation efforts to denuclearize North Korea. Furthermore, they must work to undermine North Korea's resolve to carry out provocations by strengthening diplomacy with neighboring countries such as China, Russia, and Japan; enhancing trilateral security cooperation between South Korea, the U.S., and Japan; and strengthening various forms of minilateral cooperation. In particular, the positions of China and Russia on North Korea pose challenges to the implementation of sanctions aimed at the regime’s denuclearization, requiring additional time and effort to resolve this issue. Even within the Korea-U.S. alliance, strategic concerns are also expected to arise regarding the role of U.S. Forces Korea (USFK) and the Korean military in addressing issues related to China and cross-strait relations. The two countries need to adequately coordinate on these matters to establish and implement a joint policy.

At the economic level, the government-wide and international efforts need to be integrated to effectively implement sanctions against North Korea. Domestically, additional efforts are needed to encourage cooperation between economic ministries in South Korea regarding North Korea issues. While discussions are taking place, these efforts have fallen short compared to military and diplomatic cooperation. Internationally, South Korea needs to strengthen its cooperation with the United States and apply pressure on China and Russia to ensure they implement sanctions against North Korea. Of course, such cooperation is likely to face limitations amid the ongoing U.S.-China strategic competition and the Russia-Ukraine war. Therefore, in the short term, Korea should strengthen economic security cooperation with its allies and partners to secure the competitiveness needed to take the lead in international trade and economic affairs, while in the mid- to long term, exploring opportunities for cooperation with China and Russia. 

To sustain integrated deterrence in this way, Korea-U.S. extended deterrence must be developed to a credible level amid North Korea's escalating nuclear threat. If this is not achieved, calls for redeployment of tactical nuclear weapons or independent nuclear development may gain traction domestically in South Korea. As South Korea's key ally, the stance of the U.S. administration is also critical. If the current Biden administration's policy of strengthening alliances continues, there should be no major issues. However, if the alliance policy shifts, it may become necessary to devise a new integrated deterrence strategy that aligns with this change in the strategic environment. 

□ Strengthening Integrated Deterrence Through Redeployment of Tactical Nuclear Weapons

If Korea-U.S. extended deterrence appears insufficient to counter North Korea’s advancing nuclear capabilities, integrated deterrence through “nuclear sharing” based on the redeployment of tactical nuclear weapons could be considered. If this occurs, the integration of international capabilities will be crucial, and the opinion of any one side should not be expressed as discord between parties. Since tactical nuclear weapons are also strategic weapons, a cautious approach is necessary to address the potential ramifications. 

At the military level, Korea and the United States need to engage in strategic-level discussions and reach an agreement on the operation of tactical nuclear weapons. The next step requires deliberation and discussion on when, where, and which tactical nuclear weapons should be deployed. In addition to NATO’s B61 tactical nuclear bombs, the three types of new tactical nuclear weapons currently being developed by the United States—–particularly submarine-launched cruise missiles—–could significantly contribute to strengthening deterrence. These discussions should be advanced discreetly and privately through the existing Nuclear Consultative Group (NCG).

At the diplomatic level, strategic communication is needed to reassure neighboring countries and the international community. Tactical nuclear redeployment and nuclear sharing are measures already being implemented in five NATO countries. While potentially controversial, these measures adhere to the Nuclear Non-Proliferation Treaty (NPT). Nonetheless, the reintroduction of tactical nuclear weapons on the Korean Peninsula may provoke threats from North Korea and trigger backlash from China and Russia. Therefore, proactive diplomatic efforts are necessary to manage these potential risks. Such efforts should not be undertaken by South Korea alone; they must be carried out in collaboration with Korea’s allies, including the United States, and other partners. This will help alleviate resistance from North Korea and ease pressure from China and Russia. 

From an economic perspective, it is necessary for Korea to strengthen the resilience of its domestic economy and pursue defensive international cooperation. This is because there could be another case similar to China's economic sanctions in response to the deployment of THAAD in the past. Integrated deterrence has significant implications when it comes to the economy. In particular, South Korea should cooperate closely with its allies and partners to prevent unnecessary instability in the exchange rate, stock market, and other economic sectors.

□ Integrated Deterrence Under Independent Nuclear Armament

If the introduction of tactical nuclear weapons proves insufficient to deter North Korea’s nuclear threat, South Korea may need to consider independent nuclear armament. However, from the perspective of integrated deterrence, independent nuclear armament would be a nearly impossible option without U.S. support. This is because the following preconditions would need to be met for Korea to pursue independent nuclear armament.

The assumed preconditions are as follows: First, the new U.S. administration shifts to an isolationist foreign policy and reduces overseas deployments. Second, the U.S. announces plans to scale down its troop presence on the Korean Peninsula and, at the same time, prepares to engage in dialogue with North Korea to freeze its nuclear weapons program as a means of deterring the nuclear threat. At this time, while the United States does not explicitly support its ally South Korea in developing nuclear weapons for its survival, it also does not directly oppose it. Furthermore, the U.S. signals its willingness to veto any attempt by China or Russia to impose UN sanctions against South Korea for developing nuclear weapons. There is also a possibility that Japan and Taiwan might also pursue nuclear weapons development, which could plunge East Asia into chaos. Nevertheless, the United States seeks to cope with this situation based on its own regional strategy. 

If South Korea is able to secure U.S. approval for independent nuclear armament, the two countries will need to reach a shared understanding at the military level regarding the types of nuclear weapons to be developed and their delivery systems. Even if the U.S. agrees to South Korea possessing its own nuclear weapons, it is unlikely to approve the development of ICBMs or strategic nuclear weapons, as this could create other issues at the regional level. Therefore, discussions between South Korea and the U.S. are likely to be focused on tactical nuclear weapons targeting North Korea. 

South Korea must be prepared for significant turmoil on the diplomatic front. While support from the U.S. would prevent economic sanctions from being imposed by the UN Security Council, China and Russia are likely to impose independent sanctions on South Korea. Withdrawal from or suspension of international agreements such as the Nuclear Non-Proliferation Treaty (NPT) will provoke diplomatic controversy, and efforts will also be needed to ensure a continued supply of nuclear materials. 

The situation on the economic front is likely to be just as pressing as on the diplomatic front. Therefore, Korea must mobilize all of its capabilities to maximize domestic and international cooperation. The threat posed by North Korea and serious conflicts with China, Russia, and other countries could significantly impact exchange rates and the stock market. Therefore, thorough preparation is essential to mitigate potential adverse effects on both the domestic and global economy. 

Policy Recommendations 

Integrated deterrence is a strategic concept that involves assessing the strategic environment, consolidating capabilities, and promoting international cooperation through a comprehensive understanding of national security. To effectively deter North Korea’s nuclear threat, South Korea must evaluate the overall threat it faces and determine whether its current capabilities and investments are sufficient to respond to that threat. Only then can South Korea determine the right path forward—–strengthening extended deterrence, redeploying tactical nuclear weapons, or pursuing independent nuclear armament. 

At the same time, integrated deterrence suggests that deterrence strategies should not be based on vague estimations but instead “must be quantitatively and qualitatively analyzed by relevant ministries in terms of intelligence, diplomacy, national defense, economy, and science and technology.” I recommend that these aspects be comprehensively reviewed by the Office of National Security to strengthen and implement deterrence measures. Against this backdrop, I propose the following. These are not new suggestions, nor do they deviate from the current security strategy framework. Rather, the purpose of these recommendations is to amplify the effectiveness of existing policies.

First, I recommend that the Office of National Security hold regular meetings to comprehensively plan and review the deterrence capabilities of the Ministry of National Defense, Ministry of Foreign Affairs, Ministry of Unification, Ministry of Economy and Finance, and the National Intelligence Service. Although the Office of National Security is already working on integrating the deterrence capabilities of these ministries, I suggest that the government adjust its goals to align with the changing circumstances and revise its policies based on feedback within the term of the current administration. The Office of National Security should regularly suggest specific deterrence objectives and priorities, and based on this, relevant ministries should promote shared understanding and enhance their capabilities to implement these objectives. Additionally, economic ministry officials need to change their perspective, viewing their work as also related to deterrence efforts.

Second, I recommend that the Korean government strengthen strategy and policy coordination with the incoming U.S. administration. While strengthening the ROK-U.S. alliance is one of the greatest achievements of the current administration, continued examination and coordination are essential. South Korea should take a proactive approach to communication with the U.S., taking into account the scope and level of adjustments to Indo-Pacific and Korean Peninsula policies depending on the outcome of the U.S. presidential election. Given that the U.S. is also extending its integrated deterrence strategy to issues involving China, it is highly likely to request that South Korea contribute more to China-related matters throughout the course of discussions on deterring North Korea’s nuclear threat. South Korea should carefully consider the appropriate level of contribution at the Indo-Pacific regional level and discuss how both countries can consolidate their capabilities for denuclearizing and deterring North Korea’s nuclear threat. Furthermore, Korea must be prepared to address other potential variables and related issues that may arise.

Third, I recommend that the government continue to explore creative measures to mitigate risks during the implementation of its deterrence strategy. Currently, North Korea is expected to raise barriers to dialogue and demand higher concessions for engagement. Therefore, risk mitigation efforts must be accompanied by the cultivation of appropriate conditions and careful timing. However, it is crucial to demonstrate that while responding firmly to the current situation, South Korea is also pursuing long-term efforts to mitigate risks. The focus should not be on whether dialogue occurs or how quickly it progresses. What is more important is the process of connecting dialogue to practical outcomes. Moreover, integrated deterrence can become more effective when deterrence and risk mitigation measures are implemented simultaneously.

Fourth, I recommend that the government further enhance communication with the public. The government should reassure the public by explaining that North Korea’s nuclear threat is being effectively deterred through the extended deterrence of the Korea-U.S. alliance and the development of independent, advanced military capabilities. Additionally, it should emphasize that South Korea will respond comprehensively and proactively to future changes in the security environment. The government should also convey that by integrating Korea’s national capabilities, even more effective deterrence against North Korea’s nuclear threat will be achieved in the future. Greater public support could lead to a greater consolidation of national power, which will send a more powerful deterrence message to North Korea, as it will help convince Kim Jong Un that North Korea will gain nothing by attacking South Korea.​