OPINION Trump's Korea gamble: Putting politics ahead of vital alliance

U.S. President Donald Trump’s latest moves on the Korean Peninsula should alarm Seoul — not because Washington is considering renewed dialogue with Pyongyang, but because the president appears increasingly willing to subordinate a longstanding alliance to short-term political calculations.

On the eve of the annual South Korea-U.S. military exercise, Trump ordered the Pentagon to “substantially” scale back the drills, citing their cost and allegedly provocative nature. More revealingly, he invoked his “very good relationship” with North Korean leader Kim Jong-un. He also complained that President Lee Jae Myung had declined his request for South Korean support for U.S.' military campaign against Iran. A day later, Trump said Kim had responded to his latest outreach for dialogue.

The timing is difficult to dismiss as coincidence.

Trump appears to be reviving the playbook of his first term: reduce military pressure on North Korea, emphasize his personal rapport with Kim and seek a dramatic leader-to-leader bargain. But the circumstances have changed profoundly. North Korea is more heavily armed, its nuclear and missile capabilities have advanced, and its military ties with Russia have deepened. Meanwhile, Washington is bogged down in a prolonged Iran war that is consuming military resources and exposing the limits of U.S. power to compel Tehran to capitulate.

Against this backdrop, weakening a central component of deterrence on the Korean Peninsula looks less like carefully calibrated strategy than a unilateral political gesture.

An alliance turned transactional

Trump has long viewed alliances through a transactional lens. His latest remarks make that approach particularly stark. After Lee apparently declined to involve South Korea in the Iran conflict, Trump reportedly questioned why the United States should continue protecting a country that would not assist Washington in what he described as an easy military operation.

That logic is deeply troubling.

A treaty ally is not automatically obligated to participate in every American military operation. Seoul’s decision not to enter the Iran war does not amount to a rejection of the alliance. South Korea has legitimate security interests on the Korean Peninsula and must retain the sovereign right to decide when and where to deploy its forces.

Yet Trump appears to be treating alliance solidarity as a system of reciprocal payments: If Seoul does not provide what Washington wants in one area, Washington can reconsider what it provides in another.

That is not how durable alliances work.

The South Korea-U.S. alliance has been built over more than seven decades. Its value cannot be measured by whether Seoul joins a particular American war or by how much it pays Washington at a given moment. It exists because both countries share a fundamental interest in deterring aggression and ensuring stability in Northeast Asia.

Trump’s recent rhetoric risks reducing that strategic relationship to a personal transaction.

Danger of a deal over Seoul’s head

There is nothing inherently wrong with Trump meeting Kim again. If diplomacy can reduce tensions, restrain weapons development or produce meaningful limits on North Korea’s nuclear and missile programs, Seoul should welcome it.

The danger is what Washington might be willing to concede to get Kim back to the table.

Trump could be tempted to trade reductions in U.S.-South Korean military exercises or other elements of deterrence for a temporary diplomatic gesture from Pyongyang. Washington might portray such an agreement as a breakthrough. For South Korea, however, a deal that leaves North Korea’s nuclear arsenal intact while weakening allied preparedness would look less like peace than strategic abandonment.

The Ulchi Freedom Shield military drills are not merely political signals. They are essential to ensuring that allied forces can operate together if deterrence fails. If Washington reduces its participation, Seoul must strengthen its own readiness rather than assume that presidential chemistry can substitute for military preparedness.

Politics must not dictate strategy

The timing of Trump’s pressure is particularly significant. With the Iran war dragging on and the administration facing the political consequences of a conflict that has failed to produce the swift results promised, there is an obvious temptation to pressure allies and project toughness elsewhere. As the midterm election in November approaches, Trump has every political incentive to demonstrate that he is extracting more from America’s allies while remaining capable of striking deals with its adversaries.

But South Korea should not become collateral damage in that political strategy.

Recent U.S. media scrutiny has also challenged some of Trump’s claims about the number of U.S. troops stationed in South Korea and the history of Seoul’s defense-cost contributions. Such disputes matter because public accusations can erode trust in an alliance that depends heavily on credibility and predictability.

The larger danger is that Trump’s pressure could prove self-defeating. If American security commitments can be weakened whenever an ally refuses to join an unrelated war, South Korea, Japan and European allies will have greater incentives to hedge against Washington and develop strategic autonomy. That would ultimately diminish American influence.

Lee has so far struck the right balance by welcoming the possibility of renewed diplomacy while emphasizing stronger South Korean defense capabilities. Seoul should continue on that course. It should neither blindly follow Washington into every conflict nor allow the alliance to become hostage to the preferences of one American president.

Trump’s message to Kim is clear: Washington is willing to talk. His message to Seoul is equally clear: Washington expects more.

South Korea should answer by becoming a stronger ally, not a submissive one. It should expand its defense capabilities, deepen intelligence and operational integration with the United States, strengthen regional partnerships and retain the ability to act independently when its vital interests require it.

The United States, meanwhile, should remember what it stands to lose.

Alliances are not liabilities to be renegotiated whenever political circumstances change. They are strategic assets painstakingly built over generations. Undermining one of America’s most important alliances in Asia to score political points at home or extract concessions from Seoul may produce a short-term headline, but it would weaken American power in the long run.

A handshake with Kim may make compelling television. A weakened alliance with South Korea would leave a far more dangerous legacy.

Shim Jae-yun is the chief editorial writer of The Korea Times.