Deployment of U.S. Strategic Assets on the Korean Peninsula in the Nuclear Era : Problems and Policy Alternatives 

Seong-Whun CHEON

dr.cheon@sejong.org

Visiting Research Fellow

Sejong Institute

1. Introduction: The Utility and Limits of Strategic Asset Deployment

Strategic assets are forces for “central deterrence” employed in nuclear confrontations among nuclear great powers. They symbolize the capacity to strike population centers or major industrial and military facilities thousands of kilometers away, inflicting casualties ranging from tens of thousands to millions and crippling an adversary’s war-fighting capability and will. The United States’ “nuclear triad”—intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and long-range bombers (heavy bombers, HB)—represents the quintessential category of such strategic assets.

In today’s nuclear era, in which North Korea possesses nuclear weapons, the deployment of strategic assets to the Korean Peninsula differs fundamentally from deployments during the earlier conventional era when nuclear weapons were absent. In the conventional era, strategic asset deployments functioned primarily as instruments of deterrence against North Korea and reassurance to South Korea through demonstrations of overwhelming power. The mere threat of unilateral U.S. nuclear use, rather than actual use, was sufficient to deter a non-nuclear North Korea and reassure the South.

In the nuclear era, however, the deployment of strategic assets could trigger a direct U.S.–North Korea nuclear confrontation. As a result, the United States, North Korea, China, and Russia are all compelled to consider the possibility of nuclear use on the Korean Peninsula. Unlike in the conventional era, the deployment of strategic assets in the nuclear era not only raises concerns that regional nuclear powers could be drawn into nuclear confrontation, but also increases the likelihood that an actual nuclear crisis could emerge.

This paper argues that, under conditions in which the Korean Peninsula is overshadowed by nuclear risks, the deployment of U.S. strategic assets produces negative effects that far outweigh their traditional utility and therefore cannot serve as a rational policy response to the North Korean nuclear threat. As an alternative, it presents the redeployment of tactical nuclear weapons as a more viable and credible policy option.

2. The ROK–U.S. Alliance and Strategic Assets

Within the framework of the ROK–U.S. alliance, strategic assets constitute one instrument through which the United States provides nuclear extended deterrence to South Korea. Across successive administrations, South Korea has increasingly and more explicitly requested the deployment of U.S. strategic assets. During the Cold War, deployments of U.S. strategic assets were not readily apparent to the South Korean public. However, following the sinking of the ROKS Cheonan and the shelling of Yeonpyeong Island in 2010, the frequency of strategic asset deployments gradually increased, and under the Yoon Suk-yeol administration, South Korea pressed the United States most strongly for such deployments.

3. Positions of North Korea, China, and Russia

North Korea has opposed the deployment of U.S. strategic assets since the era of Kim Il-sung. Opposition to the presence of U.S. forces capable of carrying nuclear weapons on the Korean Peninsula, along with the withdrawal of U.S. nuclear weapons from South Korea, constitutes a core element of Kim Il-sung’s injunction to establish a “nuclear-weapon-free zone on the Korean Peninsula.” This position has remained unchanged even under Kim Jong-un, despite his declaration that the historic task of completing the nuclear force has been achieved.

China and Russia argue that the deployment of U.S. strategic assets threatens not only North Korea but also their own security. At the same time, they pursue a dual strategy: tacitly tolerating North Korea’s nuclear possession on the one hand, while seeking to remove perceived threats to their own security and thereby constrain U.S. influence in East Asia on the other.

4. Problems of Strategic Asset Deployment: The Strategic Dimension

The nuclear era on the Korean Peninsula is defined by the assumption that U.S. nuclear use in response to North Korea’s nuclear capabilities and North Korean nuclear retaliation are both conceivable. As China and Russia respond on the premise that the United States could conduct nuclear operations not only against North Korea but also against themselves, strategic stability between the United States and Russia and between the United States and China may be undermined, increasing the risk of crisis escalation. The Biden administration itself raised the concern of a “deterrence dilemma” in the 2022 Nuclear Posture Review, expressing concern that U.S. responses to North Korean nuclear provocations could trigger intervention by China and Russia, potentially leading to a multilateral nuclear confrontation in Northeast Asia. It is therefore necessary to be mindful of the possibility that a crisis akin to the 1962 Cuban Missile Crisis could recur on the Korean Peninsula, or that the peninsula could devolve into a theater of nuclear contestation among the United States, China, and Russia.

The deployment of strategic assets can serve as a catalyst that deepens the deterrence dilemma. Thus, employing strategic assets in a Korean Peninsula contingency would inevitably affect strategic stability and deterrence relationships among the United States, China, and Russia, and carries a substantial risk of turning the peninsula into a playground for nuclear confrontation among great powers.

5. Problems of Strategic Asset Deployment: The Operational Dimension

The U.S. nuclear triad—intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and long-range bombers (HBs)—is ill-suited for deterring North Korea. From an operational perspective, these systems present multiple problems, including inappropriate ranges, the risk of third-party misperception, excessive destructive power, and potential violations of U.S.–Russian nuclear CBM regulations. For example, employing strategic nuclear warheads mounted on strategic assets against North Korea represents a quintessential case of projecting overkill and inherently unreliable destructive power (see Table 1).

<Table 1> Analogy Illustrating the Relationship Between North Korea’s Nuclear Threat and Strategic Nuclear Responses

In sum, U.S. strategic assets and strategic nuclear warheads cannot and should not be used against North Korea. Even in scenarios in which the use of certain low-yield nuclear warheads might be contemplated, there is neither a need to deploy them to the Korean Peninsula nor an absence of significant risks associated with such deployment (see Table 2).

<Table 2> Operational Legitimacy Assessment of Deploying Strategic Assets to the Korean Peninsula        

6. Policy Alternative: Redeployment of Tactical Nuclear Weapons

The redeployment of U.S. tactical nuclear warheads would constitute a form of nuclear extended deterrence specifically tailored to deterring North Korea on the Korean Peninsula. While the United States maintains stable central deterrence and strategic stability vis-à-vis China and Russia, South Korea would be able to rely on a credible nuclear umbrella against North Korea’s nuclear threat. At the same time, such a step would provide a key pathway for the ROK–U.S. alliance to evolve into a nuclear alliance commensurate with the nuclear era on the Korean Peninsula.

Redeployment of tactical nuclear weapons would also address an emerging concerns that the Trump administration has changed its policy for recognizing North Korea’s de facto nuclear status. In addition, it could alleviate public anxiety generated by the removal of references to the “end of the Kim Jong-un regime” from the 57th SCM Joint Communiqué and the omission of strategic asset deployment from the fifth NCG meeting last year.

Moreover, this option could garner bipartisan support within South Korea and be acceptable to a Trump administration. In 2017, redeployment was the official position of the Liberty Korea Party (now the People Power Party), making bipartisan initiatives possible under President Lee Jae-myung’s leadership through cooperation between the government, the ruling party, and the opposition. During the 2017 North Korea–U.S. nuclear crisis, it was also considered as one of the feasible options under the first Trump administration. Given the openness of U.S. officials, for example, illustrated by then–Deputy Secretary of Defense Elbridge Colby’s view that serious discussion of South Korean nuclear armament is warranted, this option could be advanced as a concrete implementation of the 2026 National Defense Strategy’s concept of “decisive but limited U.S. military support for U.S. allies.”

Considering the following factors, redeployment of tactical nuclear weapons constitutes an immediately actionable, historically validated, and practically useful policy alternative:

■ A historically proven and reliable nuclear deterrence mechanism implemented in Europe since the mid-1950s

■ A measure that reassures the South Korean public while preventing indiscriminate suffering among the North Korean population

■ A means of stabilizing inter-Korean relations on the basis of nuclear balance on the Korean Peninsula

■ A reasonable policy option that upholds the government’s commitment not to undermine the nuclear nonproliferation regime and that secures international trust

■ A symbol of the credibility of U.S. security commitments to South Korea in response to North Korea’s nuclear threat, serving as a tripwire for a ROK–U.S. nuclear alliance in the nuclear era

■ A bargaining asset that ensures South Korea’s participation in any future U.S.–North Korea nuclear negotiations

■ A cornerstone of South Korean security comparable in significance to the conclusion of the ROK–U.S. Mutual Defense Treaty in 1953 and the establishment of the Combined Forces Command in 1978