The possibility of a military contingency in the Taiwan Strait — once considered remote — has become an increasingly prominent scenario in regional strategic planning.
As tensions between the United States and China deepen and Chinese military activities near Taiwan escalate, questions are mounting about the role of US allies in the Indo-Pacific, particularly South Korea.
For Seoul, the stakes are extraordinarily high. While South Korea is a treaty ally of the US, it is not formally aligned with Taiwan and has no direct territorial or security stake in the Taiwan Strait.
Yet the geopolitical geography, alliance structure, and normative implications of a potential conflict place South Korea in a difficult, arguably inescapable, position.
Geography and the North Korea Variable
South Korea faces structural constraints that shape the contours of its Taiwan policy.
The first is geographical proximity, not just to the Taiwan Strait but also to a nuclear-armed North Korea.
A Taiwan contingency would likely divert US strategic attention and assets from the Korean Peninsula to the Western Pacific. This raises fears in Seoul of a security vacuum or opportunistic aggression by Pyongyang.
As a result, South Korea’s primary concern is not Taiwan per se, but the secondary consequences of a US-China conflict — namely, instability on the Peninsula and the potential erosion of extended deterrence.
The China Trade Trap
The second constraint is economic interdependence.
China is South Korea’s largest trading partner, accounting for roughly a quarter of its exports. Despite growing public and elite suspicion of Beijing, South Korea’s economy remains deeply tied to Chinese markets, supply chains, and investment flows.
Open support for Taiwan — especially military involvement — risks severe economic retaliation, as seen in Beijing’s response to the 2017 THAAD deployment.
While South Korea is seeking diversification through its “Strategy for a Free, Peaceful, and Prosperous Indo-Pacific,” its structural economic dependence on China makes outright alignment with Taiwan politically sensitive and economically costly.
Alliance Commitments and Strategic Reality
Despite these constraints, South Korea cannot remain entirely detached from the Taiwan question.
As a key US ally hosting nearly 30,000 American troops and critical military infrastructure, Seoul would almost certainly be drawn into any major regional conflict involving US forces.
The US Indo-Pacific Command could utilize bases in South Korea for logistics, intelligence, or rear-area support in a Taiwan scenario — whether Seoul explicitly consents or not.
Washington’s strategic planners increasingly view the region as a single, integrated battlespace, and pressure on allies to support “integrated deterrence” is growing.
This creates a scenario in which South Korea may be forced to make a high-stakes choice under crisis conditions.
Democratic Solidarity and Diplomatic Costs
There are also normative and political dimensions to consider.
A Chinese invasion of Taiwan would be a direct assault on democratic governance, international law, and the status quo — all principles South Korea publicly supports.
Remaining silent or neutral in such a crisis could undermine Seoul’s credibility as a responsible middle power and weaken its diplomatic leverage in multilateral forums.
Moreover, Japan, Australia, and other regional democracies are already deepening alignment with the US over Taiwan, forming a de facto coalition. South Korea’s strategic hesitancy could isolate it within the broader Indo-Pacific security framework.
Domestic Constraints and Military Limits
Nevertheless, full military participation in a Taiwan contingency remains politically implausible and strategically fraught.
South Korea’s military is oriented primarily toward North Korea, with limited expeditionary capabilities beyond the Peninsula.
Redirecting resources to a Taiwan scenario could weaken deterrence at home and create a dual-front vulnerability.
Public support for involvement in a Taiwan conflict is also low, with recent polls showing a clear majority of South Koreans favoring neutrality or nonintervention.
Any government decision to intervene would likely face domestic political backlash unless North Korea were clearly involved or US commitments to South Korean security were demonstrably at risk.
Strategic Ambiguity as a Path Forward
Given these tensions, Seoul’s most realistic approach lies in calibrated strategic ambiguity. This would entail reaffirming the importance of peace and stability in the Taiwan Strait, supporting international norms through diplomacy, and preparing contingency plans with the United States without explicitly committing to intervention.
Seoul can also enhance its strategic value by reinforcing rear-area support capabilities, investing in ISR assets, and coordinating cyber and space domain operations — all of which contribute to deterrence without crossing Beijing’s red lines.
In parallel, South Korea should actively engage in shaping the regional discourse on Taiwan through multilateral platforms.
Initiatives with ASEAN, the EU, and middle powers like Australia and India can help promote non-military risk reduction measures, confidence-building mechanisms, and rules-based dispute resolution.
By aligning with international law and collective diplomacy, Seoul can contribute meaningfully without assuming disproportionate risks.
Walking a Strategic Tightrope
In sum, a Taiwan contingency presents South Korea with a defining strategic dilemma. It must navigate the treacherous space between alliance expectations, national interests, and regional stability. Neither full participation nor complete neutrality is sustainable.
The most prudent path lies in crafting a multidimensional strategy that blends operational support, strategic signaling, and diplomatic engagement — while preserving deterrence on the Korean Peninsula and safeguarding national autonomy.
In doing so, South Korea can uphold its credibility as a global pivotal state while minimizing the risk of entrapment in a great-power war.
Jihoon Yu is the director of external cooperation and associate research fellow at the Korea Institute for Defense Analyses.
Jihoon was a member of the Task Force for South Korea’s light aircraft carrier project and the Jangbogo-III submarine project.
He is the main author of the ROK Navy’s Navy Vision 2045.
His area of expertise includes the ROK-US alliance, the ROK-Europe security cooperation, inter-Korean relations, national security, maritime security, hybrid threats, and strategic weapons systems.
He earned his MA in National Security Affairs from the US Naval Postgraduate School and Ph.D. in Political Science from Syracuse University.
The views and opinions expressed here are those of the author and do not necessarily reflect the editorial position of The Defense Post.
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