If South Korea develops nuclear weapons, China may take extreme measures to prevent it, potentially including missile strikes. Beijing would make such a decision not because it has a preexisting plan to do so, but precisely because it does not—Chinese leaders would be caught off guard and react swiftly.
Chinese analysts tend to underestimate both the South Korean public’s desire to develop nuclear weapons and the strategic impact of public opinion. Conversely, South Korean analysts have paid little attention to Chinese perspectives on this issue. This mutual lack of understanding could lead to catastrophic consequences. How does China perceive South Korea’s nuclear ambitions? To what extent—and why—do the Chinese worry about it? And what are the policy implications of China’s perspective for the U.S.-South Korea alliance?
It is surprising that these questions receive little discussion in South Korea or the United States. If South Korea were to develop nuclear weapons, it would most likely be linked to the withdrawal of U.S. forces. The sequence of events could unfold in either direction—South Korea might pursue nuclear armament because U.S. troops leave, or its nuclear development could trigger their departure. Regardless of which comes first, the withdrawal of U.S. forces would mean that South Korea no longer benefits from U.S. military protection. This would significantly heighten China’s temptation to take military action to eliminate South Korea’s nuclear capabilities. Given the potential consequences of such a scenario, South Korean and U.S. analysts must carefully assess China’s perspective to prevent miscalculations.
What Chinese Analysts Are Writing About South Korea’s Nuclear Debate
For this analysis, I examined a sample of 14 journal articles and expert commentaries, published in Chinese over the past few years, that discuss South Korea’s nuclear debate (See Table 1 at the end of the piece). Notably, Chinese authorities have not directly commented on the possibility of South Korea’s nuclear armament. It remains too early for Beijing to issue warnings about a scenario that has yet to materialize. While academic writings do not necessarily represent the Chinese government’s official stance, they have passed censorship and thus reflect the range of ideas the government considers permissible. As such, the Chinese-language materials referenced above provide valuable data for analyzing China’s perspective on this issue.
I find that Chinese analysts are interested in understanding the reasons behind South Koreans’ growing support for nuclear weapons and the likelihood of actual armament. However, they rarely discuss how South Korea’s nuclear armament would impact China’s security or how Beijing should respond. Even the potential for a nuclear domino effect triggered by South Korea’s nuclearization is framed as a greater concern for the United States than for China. Instead, Chinese analysts are far more worried about U.S. extended nuclear deterrence measures.
For example, Chinese experts viewed the establishment of a nuclear consultative group in 2023 and related initiatives as targeting not only North Korea but also China. They criticize U.S. extended deterrence actions—such as the deployment of strategic bombers and nuclear-armed submarines to South Korea—for undermining the nonproliferation regime in Northeast Asia. Many Chinese scholars also express concerns about trilateral cooperation among the United States, South Korea, and Japan. They worry that, as the leaders of these three nations increasingly discuss regional security issues—including Taiwan—their alliance could evolve into an “Asian NATO” aimed at countering China. Furthermore, Beijing sees the possibility of Japan joining U.S.-South Korea nuclear cooperation mechanisms—potentially forming a multilateral nuclear consultative group—as a direct threat to its security.
Chinese scholars primarily attribute South Korea’s nuclear armament debate to U.S. actions. They view growing South Korean public support for nuclear weapons as part of a broader trend in which U.S. policies undermine the global nonproliferation regime. For example, the United States has supported Australia’s acquisition of nuclear-powered submarines through the AUKUS agreement and withdrew from the Intermediate-Range Nuclear Forces (INF) Treaty, reigniting nuclear competition with Russia. From the Chinese perspective, these actions have weakened the nonproliferation framework, indirectly fueling South Korea’s nuclear ambitions. Chinese scholars do acknowledge South Korea’s security concerns regarding North Korea. However, North Korea’s nuclear development was itself a response to perceived U.S. threats in their views. If the United States reduced its military pressure on North Korea, Pyongyang would have less incentive to expand its nuclear arsenal. In turn, this would diminish South Korea’s perceived need to pursue nuclear weapons.
Chinese analysts generally assess the likelihood of South Korea developing nuclear weapons as low. Above all, they view U.S. extended deterrence as a binding constraint that prevents Seoul from pursuing nuclear armament. Additionally, many officials within the U.S. government remain committed to nonproliferation, making it unlikely that Washington would ever approve South Korea’s nuclear development. Chinese analysts predict that if Seoul were to acquire nuclear weapons, it would face international sanctions similar to those imposed on Iran or North Korea. Worse still, rather than enhancing security, South Korea’s nuclear weapons could further provoke North Korea, exacerbating the security dilemma on the peninsula. As a result, regardless of shifts in public opinion, Chinese analysts expect the South Korean government to remain rational and refrain from pursuing nuclear armament. If a progressive-leaning South Korean president were elected and resumed diplomatic engagement with Pyongyang, reduced tensions could further dampen public support for nuclear weapons.
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In my view, however, Chinese analysts tend to underestimate South Korea’s resolve for nuclear armament. They often treat South Korea as merely a dependent variable of U.S. policy, overlooking Seoul’s agency in shaping its own strategic decisions. As Wang Fudong, a Chinese scholar at the Shandong Academy of Social Sciences, correctly points out, South Korea’s nuclear debate is driven not only by U.S. policy but also by broader uncertainties in international politics. What Chinese scholars fail to fully appreciate is that these uncertainties for South Korea include concerns over China’s growing military power, lingering doubts about Beijing’s long-term intentions, and fears that the United States might one day abandon its security commitments to Seoul.
Most importantly, while South Korean public opinion may not immediately translate into actual nuclear weapons development, it can still influence U.S. nuclear policy on the Korean Peninsula. The pressure from Seoul’s nuclear debate could push Washington to reinforce its extended deterrence commitments, potentially leading to more visible U.S. nuclear deployments in the region. However, Chinese scholars have not paid much attention to these potential effects of South Korea’s public opinion.
The Memory of THAAD
In recent years, a growing number of U.S. scholars have publicly endorsed South Korea’s nuclear armament, and the idea has gained traction in policy circles. In May 2024, U.S. Senator Roger Wicker, the highest-ranking Republican on the Senate Armed Services Committee, openly argued that the United States should consider “nuclear sharing in the Indo-Pacific” or the “re-deployment of tactical nuclear weapons to the Korean Peninsula.” Even an active-duty U.S. military officer has publicly advocated for such a policy. A report that won the U.S. Strategic Command’s 2024 Deterrence Writing Award, authored by a U.S. Air Force Major, David Phillips, analyzed the costs and timeline for deploying U.S. tactical nuclear weapons to South Korea, suggesting 2031 as a possible target date. Most unpredictably, President Trump’s stance on this issue remains uncertain. Andrew Yeo, a senior fellow at the Brookings Institution, has speculated that Trump might even authorize South Korea to retain nuclear weapons.
Chinese strategists are likely to be caught off guard by these measures, which enhance South Korea’s nuclear capabilities. While full nuclear armament remains unlikely, the United States still has several policy options that could significantly strengthen South Korea’s nuclear potential. Washington could amend the U.S.-South Korea Civil Nuclear Agreement to grant South Korea the right to reprocess nuclear fuel, similar to Japan. It could support South Korea’s development of nuclear-powered submarines, as it has with Australia. It might establish a nuclear-sharing arrangement with South Korea, akin to those with European allies, or even redeploy tactical nuclear weapons. The driving force behind these discussions is the sustained public support for nuclear armament in South Korea. However, Chinese scholars tend to underestimate the influence of South Korean public opinion while overestimating Washington’s willingness to constrain Seoul’s nuclear ambitions.
If the United States pursues policies that increase the likelihood of South Korean nuclearization, China will swiftly consider retaliatory measures against South Korea. Beijing’s response would likely mirror its reaction to the 2016 THAAD deployment crisis. When the Park Geun-hye administration announced its decision to deploy the THAAD system in 2016, Chinese leadership appeared caught off guard. Beijing interpreted the move as part of Washington’s broader strategy to contain China. Similarly, if the United States were to take actions that enhance South Korea’s nuclear capabilities—whether by supporting its nuclear latency or redeploying tactical nuclear weapons—Chinese leaders would likely react with surprise and heightened sensitivity. Just as China imposed economic sanctions during the THAAD crisis, Beijing might again resort to economic retaliation. However, given China’s current economic difficulties, military responses in the Yellow Sea could be seen as a more viable option. Alternatively, China might tacitly approve opportunistic North Korean military provocations.
Talk, Not Surprise
The problem is that South Korean analysts do not pay sufficient attention to potential responses from China. In the ongoing debate on nuclear armament among South Korean experts, the primary focus is on the U.S. reaction. Much of the discussion centers on possible U.S. responses, such as economic sanctions or the withdrawal of U.S. forces from South Korea. However, there is a noticeable lack of analysis regarding China’s potential actions—whether Beijing would confine its response to economic measures or escalate to military options. To better anticipate the broader geopolitical consequences and inform South Korea’s policy decisions, it is crucial for South Korean analysts to engage more seriously and comprehensively with China’s perspectives.
While much research has been done on China’s nuclear strategy and its perceptions of nuclear arms competition in general, there remains a significant gap in studies focusing on China’s nuclear strategy toward the Korean Peninsula. Beyond understanding China’s perspective, it is crucial to increase exchanges with Chinese scholars. South Korea must clearly communicate the seriousness of its nuclear armament debate and the potential ripple effects it could have on regional security. As Tong Zhao, a senior fellow at Carnegie Endowment for International Peace, suggested, Seoul should “assist Beijing in comprehending the need to collaborate in preventing further expansion of North Korea’s nuclear capabilities.” Through such dialogue, both countries can reduce the risk of responding to each other’s actions in an unpredictable and irrational manner, thereby minimizing the chances of destabilizing escalations.
