China has been accused of "bullying" South Korea and interfering in its national security policies after laying out a series of demands linked to the deployment of US Terminal High Altitude Area Defense (THAAD) missiles.

Deployed on the grounds of a former golf course south of South Korea's capital, Seoul, THAAD is designed to intercept incoming ballistic missiles. The weapon carries no warhead and destroys missiles through impact.

The system is considered one of the best defenses available. Before he was elected, South Korea's President Yoon Suk-yeol pledged to deploy more THAAD units. In the nearly four months since he took office, he has yet to follow up on that promise, yet the issue came up when South Korean Foreign Minister Park Jin traveled to the Chinese city of Qingdao for his first meeting with his Chinese counterpart, Wang Yi. 

Emerging from their August 9 meeting, the ministers said they had agreed that THAAD should not be an obstacle to improvements in bilateral relations. Park said he had made it clear that deployment of the system was not open to negotiation as it was a "matter of our security and sovereignty against North Korea's nuclear and missile threats."

China's three demands

Seoul was therefore surprised when the following day China's Foreign Ministry declared that South Korea had agreed to limit the operations of the THAAD battery and adhere to the "Three No's" that former South Korean President Moon Jae-in had previously committed to. Those were: to not deploy more THAAD units, to not form a missile defense network with the United States, and to not formally join a three-way military alliance with the US and Japan. 

The presidential Blue House in Seoul was quick to refute Beijing's claims, declaring: "Our government clearly states that THAAD is a self-defensive tool aimed at protecting our people's lives and safety from North Korea's nuclear and missile threats and is a matter of security sovereignty that can never be subject to negotiation."

South Korean media bristled at what writers saw as geopolitical chicanery on the part of Beijing.

The conservative-leaning Chosun Ilbo declared in an editorial that "Seoul must not yield to Chinese bullying," adding that issues raised by Beijing "are not China's business and are not pledges that Seoul has any reason to adhere to."

It also pointed out that, "China has no qualms about ignoring North Korea's belligerence, but is quick to interfere with South Korea's security interests."

The Korea Herald echoed that outrage, accusing Beijing of double standards by demanding that other nations keep out of its "internal issues," such as human rights abuses in Xinjiang, the anti-democracy clampdown in Hong Kong and threats to invade Taiwan, yet has no reservations about delivering "guidelines" to South Korea on issues of national security. 

Politically symbolic deployment

"China's THAAD neurosis can be difficult to understand because it damages relations with Seoul while yielding no apparent benefit, but this particular missile defense system is politically symbolic for China," Leif-Eric Easley, an associate professor of international studies at Ewha Womans University in Seoul, told DW.

The issue has long been a source of friction between Beijing and Seoul, Easley said, with China's government insisting as far back as 2016 that deployment of THAAD would jeopardize the country's "legitimate national security interests." Beijing's concern is that the sophisticated radar would also be able to detect Chinese missile launches.

The United States and South Korea pointed out that the system is purely a defensive weapon and was necessary to protect the South from North Korea's growing missile capabilities.  

China was not mollified, however, banning tourists from traveling to South Korea and forbidding any of Korea's hugely popular K-pop music groups from performing in China. Beijing denied that the moves were retaliatory sanctions, but the two sectors were important components of the South Korean economy.  

"The Chinese Communist Party mobilized and weaponized public opinion on the issue after Chinese strategists deemed THAAD a slippery slope in terms of the US deploying advanced equipment in South Korea and linking up military capabilities trilaterally with Japan," Easley said. 

"So Beijing maintains its hard-line messaging on THAAD as if to say to Seoul: Go no further," Easley said. Though the Yoon administration is unlikely to give in to Chinese "coercion" on THAAD, he said, officials may be feeling pressure to avoid joining the US-led semiconductor alliance and working-group discussions with member states of the Quadrilateral Security Dialogue, which is made up of Japan, Australia and India, as well as the United States.

Chinese security concerns

Others say China has legitimate security concerns of its own and was merely seeking a continuation of a policy that began under Yoon's predecessor. 

"Ultimately, THAAD is perceived as a military threat to China, and what they are demanding is based on the previous government's promises," said Hyobin Lee, an adjunct professor of Korean politics at Chungnam National University.

"Furthermore, differently from the previous government, Yoon is explicitly supporting the US rather than China," Lee said. "In this situation, China has no choice but to pressure Korea. And the issue of THAAD can be one way to do that."

"And I do not believe that THAAD is for the defense of South Korea from the North," Lee said. "Rather, this is for US security interests. China and the US are in a hegemonic war situation and the THAAD issue will inevitably be sensitive. I believe the conflict between South Korea and China will continue because the South Korean government is pro-American."

Edited by: John Silk