Korea stands at a strategic crossroads. For decades, the Korea-U.S. alliance has been a pillar of national security, but that foundation now appears to be under stress. The United States, preoccupied with countering China, is advancing a “peacemaking” strategy under President Donald Trump that seeks negotiations with Russia, Iran and North Korea. In theory, a peaceful resolution with these states would be a positive outcome. In practice, however, Trump’s diplomacy is shaped by transactional thinking. It seeks to offload the burden of confronting threats onto allies while focusing U.S. resources on China. If negotiations reduce the nuclear threat to the U.S. homeland while leaving North Korea’s arsenal intact, Korea alone may be left facing that danger.

During the six-month period of political paralysis following the December 3 martial law declaration, Korea was unable to function diplomatically. Leadership vacuums prevented close coordination with the United States, even as the Trump administration was preparing for renewed talks with Pyongyang. In that context, Washington’s engagement with North Korea has moved forward — without Korea at the table. The harsh reality of international diplomacy is that if a state is not a party to negotiations, it becomes the subject of them.

With a new government now in place, Washington is expected to press Korea for increased defense burden sharing and may even revisit plans to reduce U.S. troop levels on the peninsula. These demands are not merely financial; they reflect broader questions about Korea’s role in the U.S. strategy to contain China. Depending on how Korea answers, it may either face greater costs alongside diminished security, or conversely, see enhanced deterrence, including a bolstered U.S. military presence. In this climate, strategic decision-making must be grounded in clear-headed diplomacy — one that exchanges concessions for meaningful gains.
This makes diplomacy with China even more delicate. Korea cannot afford to enter into direct confrontation, but nor can it avoid engagement under the pretext of neutrality. Passive balancing between Washington and Beijing risks a repeat of the 2016 Thaad crisis, which severely strained Seoul-Beijing relations. Worse, it could lead China to see Korea as a pliable state susceptible to pressure.

Korea must set clear red lines in close coordination with the United States, clarifying where cooperation with China is feasible and where it is not. This will reduce Beijing’s expectations of strategic ambiguity. At the same time, Korea should strengthen ties with like-minded U.S. allies such as Japan and Australia — nations that maintain their own security autonomy within the alliance framework. Recognizing that China’s core concern on the Korean Peninsula is the survival of the North Korean regime, Seoul can manage its relationship with Beijing more effectively by defining limits within which engagement can proceed.

Even if the Korea-U.S. alliance remains stable, responsibility for conventional deterrence on the peninsula increasingly falls on Korea. Progressive administrations have long supported the transfer of wartime operational control from Washington to Seoul, believing in a more self-directed defense posture. That logic once held, when Korea maintained clear superiority in conventional arms. But the rapid spread of advanced, low-cost technologies has undermined that edge. North Korea has acquired precision strike capabilities, narrowing the gap.

Warfare has entered an era of cost-efficiency. In today’s battles, inexpensive loitering drones can destroy billion-won tanks and fighter jets. Korea’s military, despite advocating manned-unmanned teaming (MUM-T), has not fully operationalized drone warfare. In contrast, North Korea has gained practical experience in drone combat by deploying troops to the war in Ukraine. Pyongyang appears to be preparing for asymmetric, high-efficiency warfare, tailored to exploit Korea’s conventional vulnerabilities.

Internally, the Korean military faces mounting challenges. Defense reform initiatives have focused more on structural and technological adjustments than on creative command models or modernized strategy. AI and drone security — issues as critical to future defense as nuclear deterrence — have not received the level of national investment required. Meanwhile, efforts to address manpower shortages have been uneven. While the conscripted soldier’s monthly salary has increased to 2 million won, entry-level officers who shoulder heavier responsibilities have not seen equivalent support.

Perhaps the greatest challenge is restoring the military’s morale and public trust after the Dec. 3 martial law declaration, which politicized the armed forces once again. Civilian control of the military and structural reform are essential. But ultimately, the defense establishment must be empowered to uphold its role as a guarantor of national sovereignty and peace.

The new administration must ensure that Korea’s military regains its confidence and purpose — not as an institution trapped in political cycles, but as a professional force laying the foundation for sustained national prosperity.

 
* The view expressed herein was published on June 5 in The Korea JoongAng Daily and does not necessarily reflect the views of The Asan Institute for Policy Studies.