South Korea’s new president could change the country’s relations with U.S. and China

South Korea’s incoming president Yoon Suk-yeol is expected to revive a conservative stance on foreign policy — and that could change the country’s relations with the U.S. and China, analysts said.

Relations with North Korea, the U.S. and China will be of particular importance, according to Tom Rafferty, Asia regional director at The Economist Intelligence Unit.

Yoon has signaled he would pursue closer relations with the United States. That could include buying another THAAD missile defense system as a countermeasure against North Korea, said Karl Friedhoff, fellow in public opinion and Asia policy at the Chicago Council on Global Affairs.

But a cozier relationship with the U.S. could affect Seoul’s relations with China, South Korea’s largest export market, Rafferty told CNBC’s “Street Signs Asia” on Wednesday.

Yoon could try to take a tougher line on China, but Friedhoff said the incoming president would soften when faced with the economic consequences.

Still, Friedhoff told CNBC’s “Squawk Box Asia” on Wednesday, before results were announced, he expects “alliance management will be smoother under Yoon,” as compared with rival candidate Lee Jae-myung of the Democratic Party.

While South Korea has historically supported social issues like human rights and democracy, Friedhoff said, the country now faces new economic trade-offs in maintaining those positions.

He said, for example, Seoul may have made itself vulnerable to Moscow’s retaliation by joining international sanctions in response to Russia’s invasion of Ukraine.

“I think the big challenge is going to be the fact that when you look at South Korean imports from Russia, roughly 60% of those imports are either crude petroleum or refined petroleum,” he said.

“Russia may turn around and try to punish South Korea for [joining international sanctions] by beginning to restrict some of those exports,” Friedhoff said.

But Yoon’s narrow win signals the country is divided on a lot of issues, said Darcie Draudt, a postdoctoral fellow at the George Washington University Institute for Korean Studies.

Yoon, the leading conservative opposition candidate, claimed victory with 48.6% of the vote, beating Lee by less than one percentage point.

“There was tepid response to [Yoon and Lee] initially as candidates, so Yoon really has his work cut out for him, as he mentioned in his acceptance speech, to unite the country,” Draudt told CNBC’s “Street Signs Asia” on Thursday.

Gi-Wook Shin, a professor at Stanford University, agreed, saying that domestic politics could be filled with a lot of tension and fights in the coming years.

While Yoon was previously South Korea’s top prosecutor, he has limited political experience.

Shin said that, combined with the opposition party holding control over the legislature, will prove to be a challenge in tackling domestic issues. The EIU’s Rafferty similarly predicted, ahead of the results, that there will be “significant checks and balances on the president’s power from the legislature given liberal control there.”

Shin said while he hoped Yoon would be able to unify Korean society, he was also skeptical about whether the conservative would be able to pull it off.

“He may get frustrated [that the opposition controls the National Assembly] and may not be able to work with them,” Shin told CNBC’s “Squawk Box Asia” on Thursday.