Seoul’s Deal with Trump Now Hinges on Two Powers in Washington
Divided US governance threatens to stall South Korea’s $350 billion investment and security pact.
1Complex Alliance Dynamics
South Korea faces a challenging diplomatic landscape as its 2025 agreement with President Donald Trump encounters a divided Washington. The deal, involving $350 billion in investments and sensitive nuclear cooperation, now faces scrutiny from an incoming Democratic-controlled Congress. Seoul must navigate these two distinct power centers to ensure the pact remains viable.
2Intertwined Economic Security
Although security and investment commitments were not legally linked, their implementation has become practically inseparable. Delays in South Korean investment projects have already hindered security cooperation discussions. Experts warn that treating these elements as separate costs rather than shared strategic gains threatens the long-term sustainability of the bilateral alliance between the two nations.
3Congressional Oversight Risks
The shift to a Democratic-led Congress introduces significant institutional obstacles for the Trump administration’s foreign policy agenda. Lawmakers can exercise oversight through legislation, appropriations, and investigations, potentially slowing down nuclear technology transfers. This creates a cycle of delays that makes fulfilling the original terms of the agreement increasingly difficult for both sides.
4Nuclear Cooperation Hurdles
South Korea seeks uranium enrichment rights and nuclear-powered submarines as key benefits of its massive US investment. However, Democrats’ strong emphasis on nuclear nonproliferation may delay these projects considerably. Any new nuclear cooperation agreement would require congressional review, allowing lawmakers to scrutinize or potentially block the transfer of sensitive technology and materials.
5Wartime Control Transition
The transition of wartime operational control before 2030 faces increased legislative monitoring. Section 1268 of the 2026 National Defense Authorization Act restricts funding for deviations from the bilateral plan. Proposed 2027 defense bills would mandate quarterly reports on readiness, further tightening congressional control over the process and complicating negotiations for the current government.
6Predictability Versus Pressure
While an assertive Congress complicates investment, it may offer more predictable trade policy and tariff adjustments. Lawmakers could provide a more rational environment where South Korea’s voice is heard. Conversely, if investment falls behind schedule, President Trump might resort to powerful pressure tactics, creating a collision between his demands and institutional constraints.
7Diplomatic Adventurism Concerns
Former ambassador Cho Hyun-dong warns of potential diplomatic adventurism from the White House. Even with a weakened domestic political position, the president retains substantial authority over foreign policy. Seoul must prepare for unpredictable moves before the new Congress takes office in January, as the administration may continue pursuing unilateral policies despite legislative opposition.
8Need for Integrated Strategy
Economist Kim Byung-yeon argues that Seoul lacks a coherent, government-wide strategy to manage the alliance. He suggests an integrated approach involving foreign affairs, security, and economic ministries is essential. By assessing defense, technology, and investment holistically, South Korea could better maximize the combined benefits of security and economic cooperation with the United States.
9Future Outlook Uncertain
The next two years are expected to be particularly difficult for South Korean diplomacy. As institutional obstacles mount, finding a compromise between Trump’s pressure and congressional oversight will be a major challenge. Success depends on whether both nations can align their strategic interests rather than viewing the alliance as a series of isolated transactions.