Lee Jae-myung won the South Korean presidential election with nearly 50% of the vote. Unlike usual, he did not get a two-month transition. He took office immediately to replace former President Yoon Suk Yeol, who was impeached last December.
Yoon had tried to declare martial law, which failed. South Koreans voted strongly against this and chose Lee instead. He promised to protect democracy and unite the nation after months of unrest.
No Time to Celebrate
Lee’s victory was quick and urgent. He now has to manage a serious problem involving the United States—specifically Donald Trump. Fixing democracy may need to wait.
Trump’s Tariffs Spark Economic Fears
In April, Trump surprised South Korea by imposing 25% tariffs on all its imports. This came after earlier tariffs on steel and cars. South Koreans had believed their close ties with the U.S. and free trade agreement would protect them.
“These tariffs could trigger an economic crisis,” said Moon Chung-in, a senior advisor to Lee.
South Korea’s economy was already slowing. Political chaos worsened it. In early 2025, the economy even shrank. Voters want economic recovery more than anything else. But trade talks with the U.S. were delayed because there was no president. That delay is over.
Security Also at Risk
South Korea relies on the U.S. for defense. America promises to protect it from North Korea, even using nuclear weapons if needed. The U.S. has 28,500 troops in the country.
However, Trump has linked trade deals with military support. In April, he wrote on Truth Social, “I discussed payment for the big time military protection we provide,” calling it “beautiful and efficient one-stop shopping.”
This strategy makes South Korea vulnerable.
Evans Revere, a former U.S. diplomat in Seoul, said, “For the first time in our lifetime, we have a U.S. president who does not feel a moral and strategic obligation towards Korea.”
Will the U.S. Pull Out Troops?
Trump once threatened to remove troops from Korea unless Seoul paid more. He may do that again. South Korea can afford to pay more, but the concern now is larger.
The U.S. wants to shift its military focus to China. American defense officials say they must prepare for possible conflict over Taiwan. To do that, South Korea might be asked to take more responsibility for its own defense.
Last year, U.S. official Elbridge Colby said South Korea must take “overwhelming responsibility for its own self-defence against North Korea.”
This could mean American troops in Korea either change focus or leave. Some U.S. officials have even suggested removing thousands of troops from Korea.
Lee Wants Balance Between U.S. and China
President Lee has long been cautious about relying too much on the U.S. He wants better ties with China, South Korea’s strong neighbor and trading partner. He has also said that Korea should avoid getting involved in a China-Taiwan conflict.
“We must keep our distance from a China-Taiwan contingency. We can get along with both,” Lee said in a recent debate.
Advisor Moon Chung-in shares the same concern. “We are worried about America abandoning us,” he said, “but at the same time we are worried about being entrapped in American strategy to contain and encircle China.” He added, “If the U.S. threatens us, we can let [the forces] go.”
The Risk of a Stormy Relationship
Former U.S. diplomat Evans Revere believes this could lead to major problems. “The two leaders may find themselves on very different pages and that could be a recipe for a problematic relationship,” he warned. “If this plays out, it would undermine peace.”
