US-South Korea military alliance needs mutual support and modernization
Roland B. Wilson
Seventy-five years after the start of the Korean War, the U.S.-South Korea military alliance stands as one of the most enduring defense partnerships in the world.
Born of blood and sacrifice, and tested over the decades, the alliance now faces an environment and region far different from the one it was designed to confront during the Cold War. While North Korea remains a primary concern, there are new challenges ranging from domestic political change, adversarial military alliances and emerging military technologies and warfare, to gray zone tactics and an increasingly assertive China.
These new and multifaceted challenges demand an alliance that is more agile, integrated and capable across multiple domains. Modernization and mutual support must be the foundation for continued deterrence and greater regional stability.
Updating the military alliance should begin with a broader approach to readiness. Joint training must evolve to include not only conventional combat operations, but also rapid response missions that integrate cyber and missile defense as well as unmanned systems.
Combined drills should be designed to test interoperability, improve command and control, and prepare U.S. and South Korean forces to respond together to a broad spectrum of security challenges, including high-intensity conflict and humanitarian relief missions. These exercises must be realistic, adaptive and reflective of the complex environments in which the alliance may operate.
Yet, recent changes in South Korea’s military posture, including the postponement of parts of the Ulchi Freedom Shield field training exercise and the purported delay or cancellation of other small-unit training exercises throughout the South Korean military, highlight growing challenges in maintaining, let alone improving, readiness.
At the same time, driven in large part by the nation’s record-low fertility rate, the size of active duty forces has reportedly declined by approximately 20 percent over the past six years, resulting in a shortfall of roughly 50,000 personnel, even with the decrease in the number of months required to serve. The combination of training disruptions and demographic decline underscores the urgency of structural transformation within the South Korean army.
Accordingly, modernization must prioritize a professional force reinvigorated by focused, domain-specific training in cyber warfare, missile defense, unmanned systems and space-based intelligence, surveillance and reconnaissance operations. Structural reforms should expand inducements for career military service and increase the number of billets to support the recruitment and retention of qualified female personnel. Finally, South Korea should implement phased-in volunteer military service programs similar to the U.S. model, offering higher education funding, professional skills training or family benefits in exchange for extended service commitments.
Investment in artificial intelligence-enabled targeting systems, secure communications and autonomous platforms will also enhance operational resilience, allowing the South Korea military to retain independent capacity while remaining fully interoperable within joint operations. These enhancements will reinforce deterrence, strengthen the military’s credibility as a capable security provider and solidify its status as an indispensable partner in the U.S.-South Korea alliance.
When it comes to cost-sharing negotiations, formally known as the Special Measures Agreement, many often view this only in terms of the funds Seoul provides to support U.S. forces stationed in Korea. Modernization, however, extends far beyond this payment framework. It requires significant investment in South Korea’s own advanced defense systems, improvements in base infrastructure and expanded joint research and development programs. Such investments would enhance both partners’ capabilities and ensure that South Korean forces are well-integrated into a shared defense strategy.
The role of U.S. Forces Korea should adapt alongside these changes. Rather than serving solely as a forward-deployed, primarily ground-based deterrent aimed at North Korea, the force should continue to be restructured as a multirole, dual-use force.
First, it must maintain and improve its ability to deter and respond to any number of North Korean provocations. Simultaneously, it must be reshaped into a mobile rapid reaction force within the broader Indo-Pacific theater. This would include expanded cooperation in maritime security to protect open sea lanes, joint counter-proliferation efforts and enhanced capabilities for disaster relief operations. These diverse missions would increase the alliance’s relevance in addressing a broad spectrum of security challenges across the region.
The Combined Forces Command (CFC) will remain a cornerstone of the alliance, but should move toward a more symmetrical partnership that reflects modernization efforts. Shifting wartime operational control from the United States to a South Korean commander within the CFC should remain a decision that is implemented in a deliberate, conditions-based manner. Such a transition would not reduce U.S. presence or capability, but would represent a more mature and confident partnership. Similarly, the United Nations Command can retain relevance by strengthening its role in multinational coordination, humanitarian assistance and disaster response.
For the U.S.-South Korea summit later this month, President Lee Jae Myung should directly address the enduring and mutually beneficial U.S.-South Korea relationship and present measurable assurances of Seoul’s commitment to democracy, free trade and regional stability. Lee needs to frame the U.S.-South Korea military alliance as much more than just the cost of stationing U.S. forces in South Korea.
He should highlight the improvements made to domestic military capabilities and outline a plan to further modernize South Korea’s forces into an agile, technologically advanced and professional fighting force. This includes ensuring that training is neither delayed nor canceled for political or appeasement purposes, but instead is used to revolutionize multidomain training and human capital development. This should consist of cutting-edge indigenous systems, which are designed to augment the alliance’s power projection and situational responsiveness.
The overall narrative should underscore how these reforms and others will help enhance regional security cooperation in areas such as maritime defense, cyber resilience, disaster relief and upholding democratic values, positioning South Korea as a vital and forward-looking full partner in shaping a stable, free and secure Indo-Pacific.
A modernized alliance would not only maintain deterrence against North Korea but also address a broader set of missions that reflect the realities of the 21st century. These include defending democratic principles and ensuring freedom of navigation and freedom from coercion. In a region where strategic competition is intensifying, the alliance’s success in support of freedom and democracy will depend on its ability to anticipate, respond and adapt to new threats while preserving the trust and unity that have defined it for decades.
The need to modernize the U.S.-South Korea military alliance is not simply about new equipment or more training; it is about shaping an enduring partnership that is ready to meet the emerging demands of today while being prepared for the unknown challenges of tomorrow.
Dr. Roland B. Wilson is the program coordinator, professor and faculty advisor for the Carter School’s Conflict Analysis and Resolution Program at George Mason University’s campus in South Korea. He is also a retired U.S. Marine and former government worker with extensive experience in East Asia.