A president who established his second term on the argument that he would place America's interests above all else is struggling to defend his actions to even his own allies, when he cuts a seven-decade-old military alliance over a personal friendship with a nuclear-armed dictator. Hours before the annual Ulchi Freedom Shield military drills with South Korea were set to begin on Sunday, Trump gave the Pentagon orders to “substantially reduce” the exercises, in reference to his “goodwill” toward Kim Jong Un of North Korea and an unwillingness of Seoul to join Washington's war against Iran. By Monday, he had a new grievance: He had demanded that South Korea pay $10 billion to cover the cost of exercises he had recently been cut, and had complained Seoul had also refused to assist with the Strait of Hormuz.

The turnaround hit foreign policy analysts on the Korean peninsula hard, as it turned the cornerstone of deterrence theory on its head since its inception in 1950. Some 28,500 U.S. troops are still stationed in South Korea to counter the North Korean threat and the combined exercises are meant to keep them interoperable and on the job. The exercises were "costly" for Trump and "totally inappropriate and hostile" to a "unthreatening and respectful" country, which he described in this regard during his term in office a description that looks very awkward against the background of the "faster and better" missile tests of North Korea and the ongoing military cooperation between the two countries, including the transfer of troops and weapons, that have helped Moscow in the war in Ukraine.

Both sides of the foreign policy establishment responded in a near-unanimous manner. Dan Fried, an assistant secretary of state under George W. Bush for European affairs, noted that he didn't see any American interest being served by the move, which undermines South Korea and Japan, worries about Taiwan and irritates NATO. Under the Obama administration, it was one of the worst-conceived ideas he could have come up with, said Danny Russel, a senior administration official who was the top East Asia official during Obama's time in office. The weakening of the regime's nuclear programme may lead the South Korean government to the belief that it is safer to have its own nuclear weapons than to rely on the protection of the United States security umbrella, warned retired ambassador Robert Wood, who noted that public opinion in South Korea has become increasingly receptive to an independent nuclear deterrent, according to a poll cited by Atlantic Council scholar Matthew Kroenig. In Washington, Sen. Jack Reed, a member of the Senate Armed Services Committee, slammed the administration as guilty of appeasement and said the move was "fickle and uninformed.

What Seoul's doing is carefully designed to prevent an open rupture. The eleven-day exercise is continuing as planned, with the Defense Ministry confirming that it was continuing to follow the schedule while officials waited for clarity about what parts Washington planned to reduce, the Mufti said. The office of President Lee Jae Myung sounded a more diplomatic tone, saying the improvement in the relationship between Trump and Kim could eventually lead to talks between Washington and Pyongyang on peace and stability, as the two discussed military support South Korea could provide in the Strait of Hormuz. That restraint is part of a more general distrustful attitude that goes back to this episode. Earlier in this year, Trump's tariff attack compelled Seoul to sign an agreement that included $350 billion to be invested in projects that would be chosen by Washington, and $100 billion in purchases of American liquefied natural gas and other energy products, in exchange for a lower tariff rate from 25 percent to 15 percent. Washington has since threatened to hike auto tariffs back up to 25 percent over lack of progress in South Korea's legislative process to implement the deal, briefly spooking the Kospi until emergency talks between South Korea's trade officials and the U.S. Commerce Department quelled fears.

Economic costs go beyond tariff schedules. South Korea's exports reached a record $709.7 billion in 2025, making semiconductors one of the biggest contributors to the country's export growth, at $173.4 billion, or about a fifth of the country's total export base and product line most vulnerable to demand from the U.S. That's why the loss of confidence in the security of the chips involved comes with a price tag: memory chip makers in Seoul have been among the most volatile stocks to move when Trump has spoken before. A security relationship that is viewed transactionally allows investors and executives to factor in much of the volatility they already are accustomed to in tariff politics.

But there's a China angle that Trump glossed over. Since his term as president, Lee has sought to improve relations with the Chinese capital by inviting Xi to his country for the APEC summit last October and calling for a “full restoration” of the China-South Korea relationship, an attitude that had already annoyed Washington hawks before the decision to host the exercise. Now, however, is the time to cut back on joint drills or to risk being seen as a sign of American security promises that can be traded for a one-on-one basis with a president's personal chemistry with an adversary, not on the basis of treaty obligations.