U.S. President Donald Trump, left, poses for a photo with Korean Ambassador to the United States Kang Kyung-wha during a ceremony for newly appointed foreign ambassadors to present their credentials at the White House in Washington on Dec. 16, 2025.WHITE HOUSE/YONHAP
Yun Byung-se
The author is former foreign minister and the chairman of the Seoul Institute of International Law.
Concerns are mounting as warning signs emerge across the Korea-U.S. alliance, which had been managed relatively well since President Lee Jae-myung took office. The tensions are particularly troubling because Lee initially made a promising start in relations with Washington and Tokyo, emphasizing security and economic cooperation with the United States alongside pragmatic diplomacy.
Now, previously acknowledged disputes and problems simmering beneath the surface are emerging simultaneously, reinforcing one another. Korean Ambassador to the United States Kang Kyung-wha's recent acknowledgment of difficulties in intelligence cooperation underscores the seriousness of the situation.
Until recently, both countries celebrated their "ironclad alliance" and its role as a cornerstone of Indo-Pacific peace. Today, U.S. warnings, visa restrictions and Korean countermeasures have produced increasingly public disagreements.
U.S. President Donald Trump warned that Korea's financial burden would double unless it promptly joined the Alaska liquefied natural gas (LNG) project. U.S. Vice President JD Vance subsequently suggested Washington would pursue the project with Korea's current or future government, or with other countries. Publicly invoking an ally's next administration is diplomatically extraordinary.
Disagreements over the conditions and timing of wartime operational control (Opcon) transfer could become equally dangerous.
U.S. Forces Korea (USFK) commander Gen. Xavier Brunson reaffirmed the principle of conditions-based transfer. He said he would obey an immediate transfer order but report the risks if military conditions remained unmet.
North Korea's advancing nuclear capabilities and changing security conditions complicate the process. Former U.S. commanders and security specialists have suggested premature transfer could affect USFK's command structure, mission and troop levels.
The Alaska LNG dispute involves U.S. domestic political considerations extending beyond existing agreements. By contrast, the Opcon transfer concerns military arrangements established through bilateral agreements in 2014, 2015 and 2018.
Disagreements over three required conditions, alongside operational planning, remain unresolved. Nevertheless, professional consultations between military authorities can bridge these differences.
A seamless transition without security gaps is essential, particularly amid North Korea's nuclear advances and technological changes in warfare. South Korea should also use this process to improve the strategic balance with its nuclear-armed neighbor.
The alliance's seven-decade history demonstrates that U.S. institutions have often resisted policies that threaten its strategic value.
Former U.S. President Jimmy Carter's proposed withdrawal of U.S. troops encountered opposition from Maj. Gen. John Singlaub, military leaders, government agencies, Congress and academics. The withdrawal was ultimately abandoned, while the Combined Forces Command was established.
During Trump's first administration, experienced officials helped restrain disruptive decisions. Such counterweights appear less influential today.
Seoul must therefore strengthen communication with the U.S. State Department, the Pentagon, USFK, intelligence agencies, the Department of Energy, Congress and think tanks. Networks should also extend to Trump's "Make America Great Again" movement, business leaders and religious communities.
Particularly troubling is the public exposure of distrust between intelligence agencies, the alliance's nervous system.
Reported U.S. restrictions on intelligence sharing over the past six months apparently stemmed from dissatisfaction with sensitive disclosures by senior Korean officials.
The dispute now extends beyond information security to counterintelligence. A senior White House official recently emphasized expectations that Korea uphold longstanding alliance standards, specifically mentioning intelligence and counterintelligence.
This could signal concerns about inadequate South Korean responses to Chinese and North Korean intelligence operations and influence activities or dissatisfaction with South Korean intelligence activities in the United States.
Opaque dealings involving neighboring powers could invite further misunderstanding. Such concerns require urgent resolution before distrust spreads throughout both countries' security establishments.
Failure to recognize these warning signs could allow tensions to become severe before Lee's term ends. Viewing every dispute merely through the relationship between trade and security would be inadequate.
A possible Trump-Kim Jong-un summit could compound the challenge, given growing strategic cooperation among North Korea, China and Russia and Pyongyang's strategy of engaging Washington while sidelining Seoul.
Strategic trust must be restored before relations reach a critical threshold.
Previous administrations offer lessons. Former President Roh Moo-hyun improved relations through Korea's Iraq deployment and free trade negotiations. Former President Moon Jae-in also eased some tensions through a summit statement near his term's end.
Today, Seoul needs an integrated strategy recognizing that different disputes require different solutions. The National Security Council should strengthen interagency coordination and ensure consistent external messaging. Careless words can create problems as readily as thoughtful diplomacy can resolve them.
Upcoming Asia-Pacific Economic Cooperation and Group of 20 summits offer opportunities to rebuild strategic confidence.
Government agencies must coordinate their efforts, avoid politicizing foreign and security policy and demonstrate bipartisan unity in defending national interests.
Such cooperation would also strengthen Korea's negotiating position on nuclear-powered submarines and uranium enrichment and reprocessing capabilities.
The alliance must not cross a point of no return. There is no room for costly trial and error.
The government must also remember that alliances depend on confidence built over decades, not simply agreements reached between leaders. Diplomatic engagement should address underlying suspicions before they harden into institutional distrust. Preserving the alliance's resilience requires sustained attention, political restraint and a shared understanding of strategic priorities.
This article was originally written in Korean and translated by a bilingual reporter with the help of generative AI tools. It was then edited by a native English-speaking editor. All AI-assisted translations are reviewed and refined by our newsroom.
