After South Korea's long adherence to a policy of "strategic ambiguity" in balancing relations between China and the United States, President Yoon Suk-yeol has made it clear that he believes following Washington's lead on the challenges facing the region is in Seoul's best interest.

During the Association of Southeast Asian Nations (ASEAN) summit in Cambodia last weekend, Yoon introduced South Korea's "Indo-Pacific" strategy, which is committed to "principles of freedom, peace and prosperity built on a rules-based order" for the region.

Yoon's strategy echoes that of the US and Japan, which have long warned of the growing threat posed by an increasingly aggressive and expansionist China.

Unveiling Seoul's forward-looking strategy for the region, Yoon emphasized that it is important to ensure the existing state of affairs is not changed "by force."  

Over the past decade, China has seized control of dozens of atolls and reefs in the South China Sea and turned them into military bases. There is also deep concern that Beijing may in the future use force to take control of Taiwan. 

In a speech in Phnom Penh on Sunday, Yoon used singled out Russia and Myanmar for thinly veiled criticism and said that "changing the status quo by force" needs to be unacceptable.

South Korea calls out China 

He also called out China, albeit obliquely, by saying that the South China Sea should be a sea of "peace and prosperity" and an area in which the freedom of navigation should be guaranteed. He also cautioned against actions that could worsen existing tensions in the region. 

"Yoon has moved quite clearly away from the policies of his predecessor in this area and the terminology that he is using is strikingly close to that of the US, although we will have to wait and see what that means in a practical sense," said Dan Pinkston, a professor of international relations at the Seoul campus of Troy University.    

"It is definitely a movement taking South Korea towards greater bilateral, trilateral and multilateral security cooperation in the region, with the US, Japan, Australia and other allied nations."

And that is a position that will inevitably "anger" Beijing, he told DW.

However, this does not mean that Yoon will take a more confrontational position towards China, which is South Korea's most important trading partner.

"It is difficult for South Korea as it has been walking this tightrope between its biggest trading partner and the nation that provided support during the Korean War and has been its most important security partner ever since." 

"But even if this new strategy is more symbolic than substantial, China is likely to react with anger."

How could China respond?

South Korea has in the past has experienced friction with Beijing after moving closer to the US strategically.

In 2016, South Korea and the US announced that they would deploy a battery of the US Terminal High-Altitude Area Defense (THAAD) anti-missile system in the South, to counter the threat posed by North Korean ballistic missiles.  

Despite protestations from Seoul that the system was purely designed to intercept threats from the North, Beijing instructed travel agencies to halt all tourist trips to South Korea and Korean musicians were no longer permitted to perform in China.  

Should Beijing respond to Yoon aligning his policies more closely with those of the US in the same way, Pinkston warned that Seoul's allies will need to provide more support than they did during the THAAD crisis. 

"At the time, there was a feeling in Seoul that the US and other countries were effectively abandoning South Korea and not providing the support it needed to stand up to China," he said.

"If push comes to shove again and China does play hardball, then I would expect to see a reinforcement and acceleration of multilateral security cooperation," he added.

Kim Sang-woo, a former politician with the left-leaning Congress for New Politics and now a member of the board of the Kim Dae-jung Peace Foundation, said he believes Yoon is leading South Korea along the correct track. 

"South Korea has been seen as the weak link in the trilateral security arrangement and Yoon cannot back down as he would be criticized at home and in the alliance with the US and Japan," he told DW.  

"There is a divide in South Korea and around half of the population supports Yoon, while the other half are behind the opposition and are in favor of closer ties with China and for connecting with North Korea, but I lean towards Yoon's position," he said. 

Kim said that although South Korea relies heavily on China for economic growth, finding alternative markets is important as China's economy encounters problems moving forward.

The nation's economic security is interwoven with its military security, he added, with technology and innovation the keys to future prosperity. 

"Technology is critical, the US is the leader and that is why we need to keep good relations with the US," he said.

Edited by: Wesley Rahn