GLOBAL ASIA

APLN member Tong Zhao co-wrote an article with Kang Jungmin and examines China’s role in shaping South Korea’s nuclear choice. The original article is on the Global Asia website.

THE RAPID DEVELOPMENT of North Korea’s nuclear capabilities has sparked unprecedented domestic debate in South Korea about nuclear options for the country’s defense. North Korea’s increasing capability to threaten South Korea with theater-range nuclear weapons and to strike the United States mainland with long-range missiles challenges the credibility of the US extended nuclear deterrence. Given that domestic polarization in the US and the evolving international geopolitical landscape may divert Washington’s attention, South Korea’s suspicions about the long-term reliability of Washington’s security commitments seem likely to persist. Although President Yoon Suk-yeol has walked back his recent public comments about considering an indigenous South Korean nuclear weapons capability, the interest and discussion will probably continue if current security trends on the Korean Peninsula remain as they are.

Given this, how might China respond to South Korea’s nuclear ambitions? How could China’s response shape South Korea’s future choices? Furthermore, what steps can regional nations and the international community take to work with China to reduce the proliferation risk and promote a stable regional nuclear order? This essay aims to examine these concerns in ways the existing literature has not addressed.

OPAQUE CHINESE THINKING ON KOREAN SECURITY

Understanding Chinese policy thinking has become harder. Not only has the government not made public statements on South Korea’s nuclear interest, Chinese policy experts have also published little analysis on this issue specifically and on Korean Peninsula security issues in general in recent years. The centralization of China’s political system and rising tensions with US-led Western countries have resulted in a restrictive domestic atmosphere that discourages Chinese experts from publicly sharing their thoughts and analysis. Since the recovery of China-North Korea relations in 2018, public analysis about North Korea and its nuclear program has become more politically sensitive than before. At the same time, China sees South Korea as a vulnerable link in the US-led alliance network in East Asia, which presents an opportunity for Beijing to compete with Washington for geopolitical influence over South Korea.^​1 This view contributes to the perceived delicacy and sensitivity of China’s South Korea policy, which dissuades Chinese experts from publicly discussing China’s perspective on security issues related to South Korea as well.

With public analysis and discussion curtailed, Chinese policy experts have fewer opportunities to thoroughly scrutinize policy options or debate potential weaknesses in existing policy. This can lead to less analytically robust policy recommendations in internal-only policy papers or memos. It also raises questions about whether there is internal agreement on a coherent, forward-looking strategy in Beijing to address Seoul’s growing nuclear ambitions.

CHINA’S POTENTIAL LEVERAGE

Given Beijing’s interest in preserving the non-proliferation regime, the obvious route for China to exercise influence is to threaten South Korea with sanctions. As South Korea’s biggest trading partner, China accounts for 27 percent of South Korea’s exports and 25 percent of its imports.² This gives Beijing considerable leverage to deter or retaliate against Seoul for pursuing nuclear weapons. South Korea is heavily reliant on imported primary energy sources, which account for 92.8 percent of its energy supply;³ on imported grains, which account for more than 90 percent of domestic needs;⁴ and on foreign investment in its stock market. South Korea is potentially highly vulnerable to economic sanctions.

However, China’s geopolitical calculus makes things more complex. Under Chinese President Xi Jinping, Beijing views the US as an increasingly existential threat. According to the mainstream Chinese perspective, the more successful China’s development becomes and the closer China comes to narrowing the power gap with the US, the more Washington would resort to extreme measures to contain and undermine China.⁵ Consequently, China has shifted from passive responses to perceived American hostility to proactive efforts aimed at reducing American regional and international influence through systemic competition and, when necessary, confrontation.⁶

As China’s foreign and security policy increasingly revolves around countering the US, Beijing is prioritizing the geopolitical objective of weakening the US-led alliance in East Asia and preventing South Korea from being fully integrated into what Beijing perceives as an America-centric, anti-China geostrategic bloc. In this context, Beijing views the US nuclear umbrella as a tool for strengthening Washington’s control over its allies and is less willing to acknowledge the positive role of US extended nuclear deterrence in dissuading allied proliferation. Chinese experts have been more critical of the recent strengthening of the US extended nuclear deterrent over South Korea than of South Korea’s expression of nuclear ambitions, revealing that enhancing the US-South Korean security alliance may be more unacceptable to Beijing than the risk of South Korean nuclear proliferation — as long as South Korea becomes strategically autonomous from the US.⁷

Ultimately, for Chinese strategists, the goals of driving the US out of the region and containing South Korea’s nuclear ambitions go hand in hand. Chinese experts have long argued that the nuclear crisis persists on the Korean Peninsula because the US has been provoking tensions with North Korea to increase its military presence and influence in the region for the ultimate goal of containing China and Russia.⁸ From this perspective, reducing American influence in the region would decrease North Korea’s interest in nuclear weapons and thus also make it less necessary for South Korea to pursue nuclear weapons.

If South Korea were to make an explicit attempt to pursue nuclear weapons, the US would have two basic policy options: either break off security ties with South Korea for violating the nonproliferation norm and impose severe sanctions, or reluctantly accept South Korean nuclear weapons. In the first scenario, if Washington chose to impose harsh punishments, including withdrawing its longstanding security commitment to South Korea, Beijing might have an incentive to apply less severe pressure than Washington on Seoul in order to move South Korea closer to Beijing. This, in turn, could cause Washington to ease its own coercive pressure on Seoul, potentially leading to the unraveling of an international sanctions regime.

In the second scenario, if Washington decided to accept and accommodate Seoul’s nuclear ambitions, it would present Beijing with a much more challenging situation. Beijing would likely become disillusioned about competing with Washington for influence over Seoul and instead adopt a much more explicitly confrontational approach toward the now nuclearized US-South Korean security alliance. China would probably impose comprehensive economic sanctions on South Korea, but Washington’s willingness to accommodate Seoul’s nuclear ambitions and maintain the alliance relationship would likely protect it from the most severe consequences.

In both scenarios, it is unlikely that major powers would successfully co-operate to force South Korean denuclearization. This geopolitical reality makes it imaginable that a determined South Korea might calculate that the punitive costs of pursuing nuclear weapons would not be prohibitively high. Recognizing this risk, the hope of preventing a nuclear South Korea and the subsequent destabilizing impact on the global non-proliferation regime increasingly rests with the effectiveness of measures to make Seoul feel secure without its own nuclear weapons

ENGAGING CHINA TO ENHANCE SOUTH KOREA’S SECURITY

To achieve this goal, the Joe Biden administration is working with the Yoon administration to build up the conventional military deterrence against North Korea, as well as to strengthen the US extended nuclear deterrence without re-introducing American nuclear weapons to the Peninsula. However, this still carries a significant risk of creating more tensions with China, as Beijing becomes increasingly sensitive to any perceived US efforts to further incorporate South Korea into the American security alliance network. To engage with China and seek Chinese understanding would still be necessary to reduce the risk of China siding more closely with North Korea and taking retaliatory measures that eventually make South Korea less secure. In this regard, Washington could redouble its efforts to clarify its nonproliferation policies to Beijing. At the same time, Seoul could start a bilateral dialogue with Beijing to build better Chinese understanding of South Korea’s security concerns.

China’s perception of US compliance with non-proliferation norms remains a key factor in shaping Chinese calculations of how it should balance non-proliferation principles and its geostrategic interests. For instance, the recent US-UK-Australia co-operation on nuclear submarines through the AUKUS agreement has reinforced China’s conviction that the US is violating nonproliferation principles in order to contain China. While a lack of domestic space in China for a balanced and factual analysis significantly contributes to this perception, it is crucial for the US and relevant allies to make every effort to proactively engage with China through substantive expert-level exchanges to address China’s worst-case speculation about the “hidden agendas” behind such co-operation. It is not an uncommon view among serious Chinese experts that the AUKUS agreement is about creating a pathway for Australia to acquire nuclear weapons.⁹

The US should directly address the popular Chinese perception that its efforts to enhance extended nuclear deterrence over South Korea are driven by Washington’s interest to contain China rather than to help South Korea address the growing North Korean threat. In this regard, Washington should minimize ambiguity in its position and more explicitly state its interest in South Korea not developing nuclear weapons. In private conversations with their Chinese counterparts, American officials should repeatedly convey the message that US efforts to enhance extended deterrence aim to help Seoul achieve security without an indigenous nuclear capability, which would also reduce the risk of Japan, Australia and even Taiwan becoming interested in nuclear weapons.

South Korea should seek a direct bilateral discussion with China about the challenges that Seoul faces in deterring North Korea’s growing nuclear threats without increasing the risk of escalation. So far, Chinese officials and experts rarely think in these terms as they typically view North Korea’s nuclear development as a self-defensive act and South Korea’s countermeasures as provocative and dictated by Washington. Driven by the goal of promoting Seoul’s strategic autonomy from Washington, China faces an incentive to demonstrate its concern for South Korea’s interests. This presents an opportunity for Seoul to assist Beijing in comprehending the need to collaborate in preventing further expansion of North Korea’s nuclear capabilities. Seoul could invite Beijing to consider how nuclear weapons states like China — in the aftermath of the Ukraine war — could provide credible positive security assurances to non-nuclear weapons states such as South Korea in the event of being threatened with nuclear weapons.

REGIONAL DIALOGUE ON THEATER NUCLEAR WEAPONS AND NO FIRST USE

South Korea’s nuclear interests remind Beijing of the negative security consequences of North Korea’s nuclear program. While China has not shown much interest in promoting a comprehensive arrangement to manage the North Korea nuclear problem, Beijing might be more open to and interested in first addressing those aspects of the program that are most problematic to China’s own interests. One such aspect may be North Korea’s significant investment in theater-range nuclear weapons, which could be particularly detrimental to Chinese interests.

Often referred to by North Korea as tactical nuclear weapons, such weapons are more relevant to regional conflicts and thus pose a greater risk of nuclear escalation in a future conventional war over the Korean Peninsula, compared to its intercontinental-range nuclear weapons that primarily threaten the US mainland. Given China’s strong concern about a nuclear war on its doorstep, it is likely to view North Korea’s theater-range nuclear capabilities as more problematic than its long-range ones. Additionally, North Korea’s theater-range nuclear weapons directly contribute to South Korea’s security concerns and its growing interest in nuclear weapons. This could also create a stronger incentive for some South Korean officials and experts to call for the re-deployment of US tactical nuclear weapons on the Peninsula, which is another major concern for China.

This presents an opportunity for Beijing to support a regional dialogue that specifically addresses theater-range nuclear weapons on the Korean Peninsula. Such a dialogue could aim to reduce the risk of nuclear use by exploring the possibility of reciprocal or joint measures of restraint. One set of measures could involve obtaining North Korea’s agreement to refrain from additional nuclear testing and set a limit on its arsenal of theater-range nuclear weapons in exchange for reciprocal restraints from Seoul and Washington, such as refraining from the re-deployment of US tactical nuclear weapons to South Korea.

Another possibility is exploring the idea of a no-first-use (NFU) zone over the Korean Peninsula, which could include political promises from the US, Russia, China and North Korea not to use or threaten to use nuclear weapons first on the Peninsula. This aligns with China’s longstanding promotion of NFU as a key measure of nuclear risk reduction. Within South Korea, there are differing opinions among experts about the US adoption of an NFU policy. If North Korea and other major powers in this region all agree to such a commitment, the security benefits could persuade Seoul to be less concerned about US commitment in this regard. A geographically limited NFU commitment would not affect US security assurances to other US allies, making it more acceptable to Washington than a comprehensive and categorical American NFU policy. If Washington and Seoul agree to support it, the ball would mostly be in the court of North Korea and China. Pyongyang may still want to maintain the option of threatening nuclear escalation in a conventional war, but this would deviate from the Chinese desire to avoid being dragged into a nuclear war started by North Korea. This presents an opportunity for Beijing to assert its regional leadership by encouraging necessary concessions from Pyongyang to achieve a goal that is very much in China’s interests. Promoting an NFU zone over the Korea Peninsula would be a relatively low-cost way for Beijing to demonstrate its commitment to maintaining regional peace and strategic stability.