The continued presence of U.S. forces in South Korea also allows Washington to maintain strategic influence in East Asia
Zaheer Mustafa
The security situation on the Korean Peninsula has become increasingly precarious, with rising nuclear threats from North Korea and growing fears among U.S. allies in East Asia regarding a potential abandonment of American security commitments. This anxiety has only intensified following the collapse of North Korea’s brief rapprochement with the United States under former President Donald Trump. In 2024, Pyongyang officially designated South Korea as an “enemy state,” further escalating tensions in the region.
North Korea’s nuclear program has long been a central threat to regional stability, with Pyongyang testing nuclear devices multiple times and developing ballistic missiles capable of reaching the U.S. mainland. These advancements have alarmed South Korea and Japan, leading to calls for stronger defense measures. South Korean President Yoon Suk Yeol, in 2023, suggested that his country might need to develop its own nuclear weapons or request the U.S. to redeploy them in South Korea. While this does not yet reflect official policy, it indicates the growing concerns within South Korea about its national security.
Public support for South Korea acquiring its own nuclear weapons has grown in recent months. A 2024 survey revealed, for the first time, that a majority of South Koreans now favor nuclear deterrence over relying solely on the U.S. military alliance. This shift comes at a time when the regional security environment is more volatile than ever, with Russia forging a “Comprehensive Strategic Partnership” with North Korea. The possibility of Russian military assistance to Pyongyang has raised serious concerns in Seoul.
However, the prospect of South Korea developing its own nuclear weapons brings several key apprehensions. Analysts argue that such a move could trigger a nuclear arms race in East Asia, with North Korea accelerating its own nuclear program and potentially motivating Japan to pursue similar capabilities. The cost of nuclear development would also be prohibitive for South Korea, likely leading to its withdrawal from the Nuclear Non-Proliferation Treaty (NPT) and inviting severe international sanctions. Moreover, continuing to rely on the U.S. nuclear umbrella may be a more pragmatic approach, as Washington’s security guarantees have long underpinned South Korea’s defense posture. Crucially, the U.S. itself remains strongly opposed to South Korea acquiring nuclear weapons, fearing that it would undermine American influence and the security framework in the region.
The Korean Peninsula’s connection to nuclear weapons dates back to the Korean War, when the U.S. threatened to use them to deter North Korean and Chinese forces. During the Cold War, the U.S. deployed tactical nuclear weapons in South Korea until 1991. South Korea’s pursuit of nuclear capabilities is also not new. In the 1970s, the Park Chung-hee regime launched a secret nuclear weapons program amid fears of U.S. troop withdrawal. Although the program was abandoned when South Korea signed the NPT in 1975, concerns over American security commitments have persisted, leading to periodic debates about South Korea’s need for its own nuclear deterrent.
The recent strengthening of North Korea’s relationship with Russia has further fueled these discussions. In June 2024, Russian President Vladimir Putin’s visit to North Korea and the announcement of mutual military assistance between the two countries alarmed policymakers in Seoul. Analysts have speculated that South Korea may seek its own nuclear deterrence in response to the deepening North Korea-Russia partnership.
Adding to the complexity, a state-funded think tank in South Korea, the Institute for National Security Strategy (INSS), recently published a report advocating for South Korea to acquire its own nuclear technology. Several conservative politicians in South Korea have also voiced support for this idea, while a group from the ruling People Power Party (PPP) has formed a forum to push for nuclear armament. Surveys show growing public support for this stance, with 44.6% of respondents in 2024 favoring nuclear weapons for South Korea, surpassing those who prefer reliance on the U.S. military.
Despite this growing momentum, significant obstacles remain. The U.S. has consistently resisted the idea of a nuclear-armed South Korea. In July 2024, South Korea and the U.S. signed an agreement to integrate their conventional forces and nuclear capabilities, but Washington stopped short of allowing South Korea to develop its own nuclear weapons. U.S. officials have expressed concern that South Korea’s nuclearization could lead to a broader arms race in East Asia and undermine the strategic balance in the region.
The U.S.-South Korea alliance, formalized by the 1953 Mutual Defense Treaty, has been the cornerstone of regional security for decades. American troops stationed in South Korea, along with the U.S. nuclear umbrella, have served as a deterrent against North Korean aggression. The continued presence of U.S. forces in South Korea also allows Washington to maintain strategic influence in East Asia. A nuclear-armed South Korea could weaken the rationale for U.S. military bases in the region and diminish American control over regional security dynamics.
Moreover, South Korea’s development of nuclear weapons could disrupt the delicate balance of power in East Asia, particularly with regard to Japan. The U.S. has long maintained a “hub and spokes” security arrangement with its East Asian allies, and a nuclear South Korea could prompt Japan to follow suit, thereby unraveling the existing security architecture. Given that American hegemony in the region has been underpinned by its nuclear supremacy, the U.S. is unlikely to support any moves by its East Asian allies to develop independent nuclear arsenals.
Another factor complicating U.S.-South Korea relations is Seoul’s deepening economic ties with China. In 2024, the two countries held a joint defense and foreign policy dialogue, underscoring their growing cooperation. China is also South Korea’s largest trading partner, and Beijing’s role in the Korean Peninsula is becoming increasingly influential. Some analysts have expressed concern that South Korea’s increasing alignment with China could complicate U.S. efforts to contain Beijing’s growing power in the region. South Korea developing its own nuclear weapons would further strain its relationship with the U.S. and increase its reliance on China, potentially weakening American influence in East Asia.
South Korea faces a challenging dilemma as it navigates rising threats from North Korea and concerns over U.S. security commitments. While the domestic push for nuclear armament is gaining momentum, the potential consequences—both economic and geopolitical—are significant. Developing its own nuclear weapons could destabilize the region, trigger an arms race, and diminish U.S. influence in East Asia. For now, the U.S. remains committed to preventing South Korea’s nuclearization, viewing it as a threat to the security order it has built in the region since the end of World War II. As tensions continue to escalate, the future of the Korean Peninsula remains uncertain, with the specter of nuclear proliferation looming larger than ever.
