As tensions escalate in the Taiwan Strait, the possibility of a full-scale crisis between China and Taiwan is no longer merely theoretical—it is increasingly being considered a plausible trigger for regional instability. In such a scenario, the Korean Peninsula would not be immune. A Trump administration, characterized by its “America First” posture, emphasis on transactional diplomacy, and skepticism of traditional alliances, would have significant implications for how a Taiwan contingency impacts Seoul. The potential ripple effects—strategic, military, economic, and political—are far-reaching.
A Taiwan crisis would inevitably draw American attention, resources, and strategic focus toward the Western Pacific. Under a Trump administration, which in the past signaled a desire to reduce U.S. military commitments overseas and reframe alliance obligations through a cost-benefit lens, such a shift could come at the expense of U.S. engagement on the Korean Peninsula. South Korea may find itself relatively marginalized as Washington prioritizes front-line support to Taiwan, particularly if Trump once again questions the utility of maintaining large-scale forward deployments in South Korea.
In this context, North Korea could see an opportunity. Pyongyang has historically acted when it perceives distraction or division among its adversaries, and a major crisis in the Taiwan Strait would be a textbook opening. Missile launches, limited provocations, or cyber operations could be used by North Korea both to advance its strategic leverage and to test the alliance’s resolve. If the Trump administration were to revert to unilateral posturing or rhetorical brinkmanship—echoing the "fire and fury" phase of 2017—without close coordination with Seoul, it could undermine the credibility of extended deterrence on the peninsula.
Further complications would arise from Trump’s well-documented approach to burden-sharing and alliance management. During his first term, he demanded substantial increases in South Korea’s contributions to the cost of hosting U.S. forces. If a Taiwan crisis were to unfold, this transactional mindset might resurface, with Washington pressuring Seoul not only for greater financial support but potentially for military or logistical contributions to U.S. operations in the Taiwan theater. Such expectations would place Seoul in an extremely delicate position, torn between its economic ties to China and its security alliance with the United States. Any overt involvement in the Taiwan issue could trigger Chinese economic retaliation, just as South Korea experienced following the 2016 THAAD deployment.
Meanwhile, economic interdependence and supply chain vulnerability add another layer of risk. A Taiwan Strait conflict could disrupt semiconductor flows and maritime trade routes critical to South Korea’s export-driven economy. If a Trump administration pushes harder for decoupling from China and seeks tighter alignment from allies on tech restrictions and trade policy, South Korea would face difficult choices—managing U.S. expectations on one side and avoiding economic coercion from Beijing on the other.
At the core of all these dynamics lies South Korea’s enduring strategic dilemma: whether to deepen alignment with the United States, even at the cost of increased entanglement in U.S.-China rivalry, or to preserve strategic autonomy by avoiding commitments that could provoke Chinese backlash. Under a Trump administration, which is likely to favor bilateral loyalty over multilateral diplomacy, Seoul would find its space for nuanced positioning increasingly constrained. The pressure to take a clearer stance in a Taiwan contingency—militarily, diplomatically, and economically—would intensify, testing the limits of its traditional balancing strategy.
While a cross-strait conflict may not be imminent, South Korea cannot afford to view it as a remote or isolated issue. If the Taiwan Strait becomes the next flashpoint in U.S.-China competition, the effects will not stop at the waters of the Western Pacific. They will echo across the DMZ, into the heart of Seoul’s security calculations. A Trump-era approach to a Taiwan crisis would likely exacerbate uncertainty, demanding that South Korea prepare now—not only with enhanced defense readiness but with clearer strategic foresight and diplomacy grounded in realism.
In an era of great-power rivalry and geopolitical fragmentation, South Korea must recognize that the first shots over Taiwan may reverberate loudly across the Korean Peninsula.
Jihoon Yu is the director of external cooperation and an associate research fellow at the Korea Institute for Defense Analyses.
