Diplomatic, security challenges lie ahead for new president

Lee Jae-myung of the Democratic Party of Korea speaks to reporters near his residence in Incheon, Tuesday. Exit polls showed Lee was projected to win the presidential election. Yonhap

When Yoon Suk Yeol was sworn in as South Korea’s president three years ago, denuclearization of North Korea still appeared within reach, China had not yet introduced its DeepSeek artificial intelligence model and Donald Trump was not occupying the White House.

With Lee Jae-myung’s election victory, he took office Wednesday amid a dramatically shifting global landscape — one defined by rising geopolitical tensions and mounting security challenges that will put his foreign policy instincts to the test.

“The complete, verifiable and irreversible denuclearization of the Korean Peninsula is no longer viable. And a nuclear-armed North Korea has become an irreversible reality for all South Koreans. Now the question for the new administration is how to live with that nuclear threat,” Cho Han-bum, a researcher at the state-run Korea Institute for National Unification, told The Korea Times.

What has also changed over the past three years is North Korea’s view of the South and the possibility of peaceful unification. In a declaration that completely reversed its decades-long stance on unification, the North said last year that it had amended its constitution to define South Korea as a “hostile state” it no longer saw as one that must be unified.

“With the special relationship gone, at least in North Korea’s view, South Korea’s new leader needs to redefine the inter-Korean relationship and manage it peacefully over the next five years,” Cho said.

All this would require South Korea to reassess its alliance with and dependence on the U.S., which the Wall Street Journal has reported might withdraw 4,500 troops from South Korea and relocate them to Guam and other bases.

Experts say South Korea’s new president should be prepared for that prospect, as well as the possibility that Trump will recognize North Korea as a nuclear-weapons state in exchange for freezing rather than terminating its nuclear program, among other scenarios.

Since the beginning of his second term in January, Trump has repeatedly said he would seek to resume diplomacy with North Korean leader Kim Jong-un.

“This security issue is interrelated with trade and tariffs. Trump may try to negotiate it all at once, including the issue of reducing troop levels in South Korea,” said Ma Sang-yoon, professor of politics at the Catholic University of Korea. “The new president should be prepared for all likely scenarios and, if possible, persuade Washington to reflect our position and view in formulating its North Korea policy.”

Under the Yoon administration, South Korea failed to make any meaningful improvements in relations with China, which have been strained since Seoul’s decision to allow the U.S. to deploy its Terminal High Altitude Area Defense (THAAD) system, a sophisticated missile defense battery designed to intercept incoming ballistic missiles, here in 2016.

On a positive note, there is room for improvement. But Seoul must reckon with the influence of Washington, which increasingly reorients its trade and military strategies to focus on deterring China’s rise and expansion, said Chung Jae-heung, a China expert at the Sejong Institute, a think tank.

“China today is more powerful and more technologically advanced and, most importantly, it needs South Korea less,” Chung said. “It is a global leader in key future industries, including electric vehicles and artificial intelligence. Given that South Korea has fewer things to offer, I’m doubtful the current government strategy of strengthening ties with China only in economic areas will be sustainable.”

For the new president, this means a delicate balancing act to maintain economic cooperation with China without upsetting the alliance with Washington.

In a message aimed at countries seeking economic ties with China and defense cooperation with Washington, U.S. Defense Secretary Pete Hegseth said during Saturday’s Shangri-La Dialogue in Singapore that their economic dependence on China deepens the country’s “malign influence and complicates our defense decision space during times of tension.”

As Russia and Ukraine seek a ceasefire deal, experts also say the new administration should develop a diplomatic strategy after the potential end of the war.

“The conflict will end in a ceasefire sooner or later. This could open opportunities for South Korea in Russia, whose diplomatic options are currently limited under President Vladimir Putin,” Cho said. “We need to be prepared for it."