South Korea’s Taiwan Conundrum

rok taiwan

What would South Korea do if China attacked Taiwan? Many people in Washington, Taipei, and Tokyo are wondering. South Korea’s position remains much more ambivalent than Japan’s. Seoul is understandably more worried about the possibility of retaliation from China, akin to Beijing’s fury over the basing of a U.S. defensive missile system in South Korea several years ago. Seoul also has a unique concern that Beijing would turn even more non-cooperative in the future process of Korean unification, if it ever occurs, as a result of South Korean involvement in a war over Taiwan. However, there is a variety of scenarios for a Taiwan contingency that will impact South Korea’s security policies, especially the one involving a two-pronged war in both the Taiwan Strait and the Korean Peninsula. Seoul should more actively engage in strategic dialogue with Washington on Taiwan issues. In turn, Washington should better appreciate Seoul’s concerns and the possible range of South Korea’s role in the Taiwan Strait. Both parties are urged to include a Taiwan contingency as part of the agenda for the bilateral alliance.

So, What Does South Korea Think?

As the possibility of war across the Taiwan Strait looms large, the analytic community in Washington has begun to ask questions about South Korea’s position. Experts have called for Washington to reinforce security cooperation with allies and like-minded countries to deter China’s invasion of Taiwan. They especially emphasize that Japan’s backing is indispensable. In turn, Tokyo has shown an unprecedented level of support for Japan’s involvement in a Taiwan contingency. During the U.S.-Japanese summit in April 2021, President Joe Biden and Prime Minister Yoshihide Suga demonstrated a united front on the Taiwan matter. Deputy Prime Minister Aso Taro also remarked that a Taiwan contingency is linked to Japan’s survival. As Tokyo clarifies its position, a growing attention is paid to South Korea.



The United States has military and political interests in South Korea’s position for the possibility of U.S. Forces Korea’s involvement in a Taiwan contingency and South Korean military forces’s potential support. General Paul LaCamera, the commander of U.S. Forces Korea, stated during the confirmation hearing in May that he would seek to integrate U.S. forces based in South Korea into “operational plans supporting U.S. interests and objectives in the region [emphasis mine].” Any U.S. military operation from the peninsula to intervene in order to defend or retake Taiwan would require close coordination with the South Korean government. This observation begs a set of questions regarding South Korea’s internal view of the Taiwan issue. Why does South Korea seem to prefer ambiguity? How does China view South Korea’s involvement in the Taiwan contingency? How do members of South Korea’s policy community assess the possibility of a war over Taiwan and what South Korea ought to do?

Why Take a Cautious Approach?

During the summit in May 2021, Presidents Biden and Moon Jae-in agreed on the importance of “preserving peace and stability across the Taiwan Straits.” It was the first time that the Taiwan issue was ever included in a joint statement between South Korea and the United States. During the press conference, Moon reiterated that South Korea would work more closely with Washington on this issue. In the domestic briefing on the outcome of the summit, however, South Korean Foreign Minister Chung Eui-yong remarked, “We are fully aware of the unique relations between China and Taiwan. Our government’s stance has not changed. We’d like to reiterate that regional peace and stability is the common wish shared by everyone in the region.” Chung practically toned down the significance of the inclusion of Taiwan in the joint summit statement. As such, South Korea’s commitment to the defense of Taiwan largely remains ambiguous.

The possibility that China might attack Taiwan emerged as a thorny issue in the alliance for the first time during the Roh administration. Due to the increasing demands of military commitments in the Middle East, the Bush administration developed the concept of “strategic flexibility” and applied it to U.S. Forces Korea. Washington intended to rapidly move select U.S. military assets out of the Korean Peninsula to wherever these forces were needed. South Korean policymakers worried that these forces might be dispatched to Taiwan in the event of military conflict. That could threaten to entrap South Korea in a war between the United States and China. President Roh Moo-hyun publicly expressed his strong opposition against such a scenario. On Jan. 19, 2006, however, the South Korean government agreed to acknowledge the “strategic flexibility” of U.S. Forces Korea under the condition of consultation. In the joint statement, Foreign Minister Ban Ki-moon affirmed that South Korea respected the “necessity for strategic flexibility” while Secretary of State Condoleezza Rice affirmed that “the U.S. respects the [Republic of Korea] position that it shall not be involved in a regional conflict in Northeast Asia against the will of the Korean people.”

No doubt, South Korea’s cautious approach is related to China’s potential retaliation. During a bilateral summit in May, China’s Global Times editorial warned that Seoul’s discussion of Taiwan with Washington is equal to South Korea drinking poison under U.S. coercion. After the summit, the spokesman of the Chinese Ministry of Foreign Affairs also warned that the “relevant countries” should not “play with fire.” Chinese analysts interpreted the inclusion of the Taiwan issue in the joint statement as Washington’s ploy to expand the role of the U.S.-South Korean alliance to “contain China.” A report published by the China Institutes of Contemporary International Relations, for example, argues that the Biden administration agreed to scrap the ballistic missile range limits for South Korea precisely to balance China’s missile capabilities. The authors claim that China should take necessary measures to raise the cost of South Korea’s cooperation with the United States on Taiwan. With China’s economic retaliation over the U.S. deployment of the Terminal High Altitude Area Defense system in 2017 still in fresh memory, it is not surprising that Seoul needs to take into account China’s likely retaliation when formulating its position on Taiwan.

From a longer-term perspective, Seoul also needs to consider Beijing’s policy toward Korean unification. After the end of the Vietnam War, China and Korea remain the only divided countries in the Asia-Pacific region. Chinese officials and scholars emphasize that the unification of Korea is an international issue, whereas Chinese-Taiwanese unification is an internal affair. The two Koreas joined the United Nations as two sovereign states in 1991. Despite the difference in legal status, Chinese experts tend to positively perceive that Korean unification, if it happens first, would stimulate the Chinese people’s aspiration for national unification. They even expect that Beijing may learn some lessons from the Korean experiences of integrating two different systems. In short, Chinese analysts see a linkage between Korean unification and Chinese unification. This implies that China will surely accuse South Korea of obstructing China’s national unification if the country gets involved in a Taiwan contingency. Then, Beijing will become even more non-cooperative in the process of Korean unification in the future.

China’s cooperation is crucial to maintaining stability on the Korean Peninsula if the unification of the two Koreas ever occurs in the future. From the U.S. perspective, securing North Korea’s nuclear infrastructure and arsenal would be the top priority in the event of Korean unification. As I argued elsewhere, Washington and Seoul can coordinate efforts to shape Beijing’s policy toward Korean unification once they have a comprehensive understanding of China’s cost-benefit calculus in association with Korean unification. However, if South Korea is involved in contingency planning for Taiwan affairs, such a move would surely diminish Beijing’s willingness to cooperate for Korean unification. The linkage of unification issues is therefore a unique concern to South Korea that other U.S. allies do not have to worry about.

A Dangerous Linkage

The challenge is that the contingency in the Taiwan Strait may have a direct impact on South Korea’s national security as well. South Korea’s analytic community appears to have mixed assessments on the possibility of war across the Taiwan Strait. South Korean scholars notice that the Chinese leaders’ aggressive remarks on Taiwan have visibly increased under General Secretary Xi Jinping’s watch. But they also interpret that such a rhetoric is developed for domestic consumption: Xi attempts to strengthen popular support by appealing to the Chinese people’s aspiration for national unification. Even if Xi has a genuine desire to pursue unification by force, the disparity with U.S. military forces still remains large, which will become even larger with the addition of U.S. allies like Japan, Australia, and the United Kingdom. Xi therefore has to take into account the political, economic, and diplomatic consequences before making a decision on China’s invasion of Taiwan. Therefore, South Korean scholars seem to conclude that China is not likely to invade Taiwan anytime soon and will focus on maintaining the status quo instead.

What South Korea needs to worry about, however, is not the low possibility of a rapid and all-out invasion, but the likelihood of limited attack or low-intensity provocation in slow motion. For example, the unclassified tabletop exercise — funded by Japan’s Sasakawa Peace Foundation and joined by experienced military experts from Japan, South Korea, Taiwan, and the United States in 2020 — started with a hypothetical situation that China occupies two Taiwan-controlled features in the South China Sea. The permanent garrisons on the islands of Taiping (Itu Aba) and the Dongsha (Pratas) are small and lightly armed. The Chinese military can quickly occupy them, justifying the actions with its “One China” policy. Since the occupation does not involve any American casualties with the number of Taiwanese casualties kept low, it will be hard for Washington to make a rapid decision for military intervention. While holding hostage the Taiwanese people on the islands, Beijing can pressure Taipei and Washington to refrain from taking any actions to retake the islands. The 2021 report published by the Center for a New American Security also reached a similar conclusion that China’s limited attacks will put the United States in a very difficult position to react. Both the Sasakawa exercise and the Center for a New American Security report urge Washington to discuss with U.S. allies about their potential assistance in such scenarios, which means that Seoul needs to be ready to have such a conversation.

The worst-case scenario for South Korea would be that the Taiwan contingency expands to a crisis on the Korean Peninsula. If the tension rapidly escalates to the verge of military conflict with the United States in the Taiwan Strait, China would certainly want to prevent the U.S. forces based in Japan and Korea respectively from repositioning themselves to intervene in and around Taiwan. Therefore, if Pyongyang intends to do so, Beijing will not oppose North Korea’s concurrent provocations to pin down U.S. Forces Korea and U.S. Forces Japan from moving to the Taiwan Strait. From Pyongyang’s perspective as well, the contingency in Taiwan Strait means that the U.S. focus is distracted from the Korean Peninsula, which creates an opportunity for major provocation such as nuclear or long-range missile tests. By doing so, Pyongyang can pressure Seoul and Washington to make concessions on the denuclearization negotiation. As U.S. Navy officer Ki-suh Jung persuasively argues, China and North Korea, as treaty allies, may well discuss, plan, and execute a two-pronged attack to split the U.S. forces. With or without such a conspiracy, Pyongyang can send a signal to Beijing for simultaneous attacks at any phase of crisis. Indeed, in October 2021, North Korean Vice Foreign Minister Pak Myong-ho threatened that “The huge forces of the U.S. and its satellite states, which are being concentrated near Taiwan,” can be “committed to a military operation targeting [North Korea] at any time,” and that “The U.S. should bear in mind that its reckless interference in internal affairs…would only invite tragic consequences.”

A Test of the Alliance

When North Korea invaded South Korea on June 25, 1950, American leaders rapidly decided to support South Korea’s defense. It should not be forgotten that President Harry Truman also directed the U.S. Seventh Fleet to the Taiwan Strait to prevent conflicts between China and Taiwan. The United States could easily deter China’s invasion of Taiwan in 1950, but this may not be the case anymore in 2021. The debate over when, whether, and how China might attack Taiwan — and what such an attack might lead to — has taken on a new sense of urgency in the last two years. As such, Seoul needs to communicate more actively with Washington on Taiwan-related issues, including how to respond to China’s possible retaliations. In the case of all-out war, South Korea would be surely expected to fight with the U.S. forces as a treaty ally. In the case that a conflict in the Taiwan Strait expands to the Korean Peninsula with North Korea’s provocation in support of China, South Korea and the United States need to discuss whether and how to distribute U.S. forces assigned to Korea and South Korean forces between the two front lines. And in the case of low-intensity provocations or limited attack, Seoul needs to explain and seek mutual understanding with Washington if it is unwilling to be involved militarily. Then they can explore other ways for South Korea to make contributions for the stability of the region.

The Senate hearing of the U.S. Forces Korea commander in May was revealing about the growing expectation of South Korea’s role in Northeast Asia. As the 10th-largest economy with the sixth most powerful military, South Korea is well expected to make contributions for peace and stability in the region. That is why Gen. LaCamera said during the hearing that, “given…the international reach of the South Korean military, opportunities are emerging for alliance cooperation beyond the Korean Peninsula.” Too much expectation, however, may end up with a deeper disappointment if not managed properly. Seoul needs to take the Taiwan issue more seriously and review its policy options. It should communicate with Washington more actively to explain its concerns and possible range of policy options. Washington also needs to better understand South Korea’s view to have a productive dialogue. Regardless of a real possibility of a Taiwan contingency, the trust level of the U.S.-South Korean alliance is already being tested.



Sungmin Cho, Ph.D., is a professor at the Daniel K. Inouye Asia Pacific Center for Security Studies, an academic institute of the U.S. Department of Defense. The views expressed in this article are the author’s alone and do not reflect the official positions of his employer or the Department of Defense.

Image: U.S. Navy (Photo by Seaman Apprentice Cale Hatch)