South Korea president Lee aims to tamp down tensions with Trump

On August 25, South Korean President Lee Jae-myung will be visiting the White House for his long-anticipated first summit with President Donald Trump.

Having launched his presidency only in June, Lee hopes to use the summit as an opportunity to build a positive, cooperative relationship with Trump — a crucial diplomatic counterpart with whom he must learn to work to advance the U.S.-ROK alliance and achieve shared goals in the years to come.

The new trade deal that Seoul and Washington reached late last month will likely take center stage. The deal involves lowering U.S. tariffs on South Korean goods from 25% to 15% in exchange for South Korean investments in key American sectors, most notably shipbuilding, as well as purchases of U.S. energy products and ensuring greater access to the South Korean market for American cars and agricultural products.

Lee and Trump are expected to review the various aspects of their deal and formally announce it to the public.

While the trade deal will contribute to creating a positive atmosphere, several pending complex alliance issues could raise tensions, particularly regarding how the financial and military burdens of sustaining the alliance will be shared into the future.

Trump has long suggested that America’s allies have been free-riding on Washington’s extended deterrence and has called on U.S. allies to dramatically increase their defense spending and overall financial contributions. “If they don’t pay, I’m not going to defend them,” Trump has warned in the past. South Korea has been no exception.

During his first term, in an apparent bid to press Seoul into paying significantly more for the stationing of U.S. Forces Korea, Trump ordered the Pentagon to consider withdrawing them. Trump raised the issue again during last year’s presidential campaign, suggesting that South Korea should pay up to ten times what it is paying now.

If Trump brings it up again, Lee will likely agree on the need to enhance South Korea’s financial responsibility for the alliance. Anticipating that likelihood, in advance of the summit, Seoul has been reportedly preparing a concrete plan to accommodate Trump’s demands, including a multi-year commitment to increasing South Korea’s defense spending.

Whether that proves sufficient to satisfy the U.S. president remains to be seen, although both sides should be prepared to compromise.

When it comes to burden-sharing, the more contentious issue could be whether there is agreement on the strategic priorities for U.S. forces based in South Korea. Trump’s Pentagon has stressed its intention to “prioritize” deterrence and warfighting against China and concentrate its forces on that goal. A number of the administration’s defense officials and military strategists have publicly urged shifting the operational focus of U.S. Forces Korea from North Korea to China — including responding to a potential Chinese invasion of Taiwan — and placing South Korean forces predominantly in charge of deterring North Korea.

This idea of expanding the so-called “strategic flexibility” of U.S. Forces Korea is likely to draw resistance from Lee if Trump raises the issue. The concept is unpopular in South Korea for quite obvious reasons; it heightens the danger of the country being pulled into an unwanted war with China while degrading military readiness against North Korea.

A recent survey found that South Koreans would overall strongly oppose the deployment of U.S. Forces Korea for regional conflicts with China that do not directly involve South Korea. Only 6% of South Koreans supported allowing U.S. Forces Korea to be deployed for combat operations in the event of a conflict over Taiwan, and only 14% approved of U.S. Forces Korea carrying out military operations in response to China’s use of force outside Korea more broadly.

Lee himself shares this reservation. As a presidential candidate, Lee said that South Korea should not be involved in any conflict in the Taiwan Strait.

To be sure, the issue of strategic flexibility may not be entirely non-negotiable for Seoul. In the survey, 42% of South Koreans approved of U.S. Forces Korea playing a limited, non-combat support role in a Taiwan conflict, hinting at some room for compromise. However, with South Koreans first and foremost concerned about the threats posed by North Korea’s nuclear advances, conversations regarding strategic flexibility will inevitably feature disagreements.

In any case, if Trump's defense planners press the Lee administration on the issue too hard or too impatiently, they are likely to encounter serious resistance.

Instead of spending too much energy trying to get South Korea to pay an exorbitant cost for stationing U.S. troops or to subordinate its core security interests to support U.S. war-planning against China over Taiwan, the Trump administration would be wise to prioritize issues where mutual interests and strategic convergence are relatively clear. One such issue is pursuing diplomacy with North Korea.

Both Trump and Lee share a strong interest in engaging North Korea. Since entering office, Trump has repeatedly expressed his desire to resume nuclear talks with the North Korean leader, Kim Jong Un. Likewise, Lee, convinced that “peace is better than war, no matter how expensive,” is keen to pursue dialogue with Pyongyang and improve inter-Korean relations that have been severely strained in recent years, with the goal of eventually moving the regime toward nuclear disarmament.

According to a report published earlier this week, Washington and Seoul have been coordinating to demonstrate bilateral support for dialogue with North Korea in the joint statement, possibly including an endorsement of the 2018 Trump-Kim Singapore Declaration. This would be a positive first step.

That said, both Trump and Lee also face a common challenge: how to bring Pyongyang back to the negotiating table. Pyongyang has consistently rebuffed diplomatic overtures from Washington and Seoul, reiterating that it will “never” give up nuclear weapons. And time seems to be on Pyongyang’s side. Having developed an unprecedentedly tight alliance with Russia since Moscow’s invasion of Ukraine in 2022, Pyongyang does not appear particularly eager to engage in diplomacy with either the United States or South Korea.

Despite the overall pessimistic outlook, however, a path to diplomacy with North Korea may still exist. Pyongyang has signaled that it may be open to talks not conditioned on denuclearization. Indeed, moving away from the goal of denuclearizing North Korea will be hard for both Seoul and Washington. But it is a possibility that the Trump and Lee administrations should face and explore together, given the harsh reality that decades of efforts to denuclearize North Korea have all but failed.

While accepting that North Korea will get to keep nuclear weapons is disturbing, the alliance in fact has already been living with an increasingly nuclear-capable North Korea. Diplomacy with Pyongyang for more modest goals — aimed at preventing further nuclear buildup and promoting arms control — may be the only viable way forward, and the Trump and Lee administrations might have a lot less to lose from pursuing this path than they imagine and fear.