What’s Causing the Rise in China-South Korea Tensions?

Verbal jousting between China and South Korea escalated in recent weeks amid moves by the Yoon Suk Yeol administration to strengthen South Korea’s alignment with the United States. China has previously regarded South Korea as a weak link among the United States’ Asian alliance partners and could be tempted to pursue policies aimed at magnifying differences between Washington and Seoul.

What are the recent signs of China-South Korea frictions?

Chinese media outlets have criticized South Korea’s efforts to join U.S.-led initiatives—such as the Indo-Pacific Economic Framework and the “Chip 4” dialogue among semiconductor manufacturers, including Japan and Taiwan—since Yoon’s inauguration in May 2022. However, frictions intensified in March when Chinese media began to circulate criticism of South Korea’s efforts at rapprochement with Japan. And on April 20, the Chinese government responded harshly when Yoon characterized a possible cross–Taiwan Strait conflict as an international security issue. It launched formal diplomatic protests warning South Korea not to abandon its One China policy.

The Chinese government’s criticisms came to a crescendo on June 8 with Chinese Ambassador to South Korea Xing Haiming’s public comments that “those who bet on China’s loss will surely regret their decision in the future.” This statement—delivered in a meeting with opposition leader Lee Jae-myung of the Democratic Party of Korea—sparked a diplomatic firestorm in South Korea, where it was widely regarded as a threat to punish Seoul for strengthening its alignment with Washington.

How has South Korea responded?

President Yoon directly criticized Ambassador Xing for pursuing political incitement rather than trying to build bridges between the two countries. Representatives of the ruling People Power Party called on the government to declare the Chinese ambassador persona non grata. The public souring of South Korea’s relations with China could impede longer-term efforts to restore diplomatic equilibrium or sustain senior-level diplomatic engagement. At the same time, National Security Advisor Cho Tae-yong has publicly reiterated the Yoon administration’s desire to establish a relationship with China that upholds common interests based on “mutual respect and common interests.”

What do these tensions mean for the U.S.-South Korean alliance?

On the heels of this apparent rupture in China-South Korea relations, U.S. Secretary of State Antony Blinken visited Beijing in an effort to establish “guardrails” on the intensifying U.S.-China strategic rivalry. His meetings there constituted the most in-depth and comprehensive discussions of Washington and Beijing’s recent disputes. However, the two sides do not yet appear to have established a common understanding of how to manage competition.

Meanwhile, China-South Korea tensions over security issues appear to be expanding. Competition and occasional conflict between Chinese and South Korean fishing vessels have periodically strained the relationship. In addition, Chinese military incursions into South Korea’s exclusive economic zone and its air defense identification zones have increased in frequency, though they are not always reported.

Beijing could be tempted to try to drive a wedge in the U.S.-South Korea relationship by punishing Seoul for moving closer to Washington. South Korean security strategists still chafe at China’s economic retaliation against the 2017 decision to allow the United States to deploy a Terminal High Altitude Air Defense (THAAD) battery in South Korea. There is also a widespread perception in South Korea that the United States made virtually no effort to defend South Korea against China’s actions.

Renewed retaliation against South Korea could have unintended consequences. While the Yoon administration has an interest in limiting its exposure to potential political or economic retaliation by Beijing, a sustained downward trajectory in China-South Korea relations could remove South Korea’s remaining inhibitions about normalizing the U.S. deployment of THAAD batteries on the peninsula or boosting trilateral security cooperation with the United States and Japan. For instance, the Yoon administration could become more inclined to participate in developing a regional missile defense system or enhancing multilateral defense cooperation, steps that China attempted to discourage in talks with the previous Moon Jae-in administration.