Shifting U.S. security priorities put Korea-U.S. alliance under strain

 
Choi Yoon-hee 

The author is president of the Sea  Power League of the Republic of Korea and former chairman of the Joint Chiefs of Staff

 
The Korea-U.S. combined defense system is the foundation of the Republic of Korea’s national security, designed to deter and respond to threats from North Korea. It includes the United Nations Command, the Combined Forces Command, wartime operational control (Opcon), South Korean forces, and United States Forces Korea (USFK). Yet growing concerns have emerged regarding the future of this alliance, especially in the wake of the Donald Trump administration’s foreign policy shift.
 
A report released Thursday by former U.S. defense officials, including Dan Caldwell, recommended reducing U.S. ground combat troops in Korea and scaling back U.S. air squadrons — cutting the total U.S. troop presence from 28,500 to just 10,000. Earlier, Elbridge Colby, former deputy assistant secretary of defense, stated that “the United States has no reason to get involved in a major conflict with North Korea.” These views reflect a broader shift in Washington, where discussions about redefining USFK’s role, accelerating Opcon transfer and increasing Seoul’s financial burden are gaining traction.
 

 
Some reports suggest that the UN Command could relocate from Seoul to Japan with a U.S. commander stationed in Japan assuming leadership. Such moves would mark a significant shift in the security posture on the Korean Peninsula. These developments echo the former Acheson Line, which excluded Korea from the U.S. defense perimeter — a mistake that led to a major miscalculation by the North.
 
There are two key ways to interpret recent U.S. moves. First, the United States is struggling to counter China’s growing influence while maintaining global commitments. China’s maritime expansion threatens U.S. naval dominance, a core pillar of American strategic interests. Second, Washington may be signaling its discomfort with Seoul’s inconsistent policies toward the U.S. and China, which shift with each new Korean administration.
 
U.S. Secretary of Defense Pete Hegseth’s statement at the Shangri-La Dialogue on May 31 — “There is no such thing as relying on the U.S. for security and China for the economy” — was a clear rebuke of Korea’s perceived policy of “security with the U.S., economy with China.”
 

 
Regardless of administration changes, countering China remains Washington’s top strategic priority. However, the United States is no longer as dominant as it once was. China continues to expand its maritime presence, having constructed artificial islands in the South China Sea and now installing permanent structures in the Yellow Sea. China’s naval strategy includes establishing ports in 12 countries, which could soon double as military bases.
 
In contrast, the U.S. shipbuilding industry has declined since the Ronald Reagan administration ended subsidies for the sector following the Cold War. Today, the United States has fewer than five functioning shipyards while China’s shipbuilding capacity is 230 times greater. As of the early 2020s, China possessed about 7,000 merchant vessels capable of transporting military goods, compared to just 82 in the United States.
 
If conflict were to erupt in the Taiwan Strait under these conditions, the consequences could be disastrous. When I accompanied U.S. Navy Secretary John Phelan on a visit to HD Hyundai Heavy Industries in May, I saw firsthand how concerned U.S. officials were about this imbalance. Washington’s new SHIPS Act seeks to rebuild maritime strength, but restoring the industry will take decades. In the meantime, the United States is turning to Korean shipbuilding — a rare strategic opportunity that Korea should leverage in security and trade negotiations.
 
At the same time, Korea must anticipate U.S. pressure to shoulder more of its defense burden. This includes more than just increased contributions to USFK. On June 28, U.S. Forces Japan Commander Stephen Jost wrote in the Japanese press that U.S. command authority in the region would gradually expand. He also mentioned the possibility of relocating the Combined Forces Command to Japan. While UN Security Council Resolution 84 of 1950 does not specify the command’s location, such a move would shift the UN Command’s focus from Korean Peninsula deterrence to broader regional management.
 
 
The geopolitical value of the peninsula is rising amid intensifying rivalry between the U.S.-Japan-South Korea bloc and the North Korea-China-Russia axis. Still, U.S. decisions are likely to be made unilaterally, regardless of Korea’s views. It would not be the first time. In 1969, President Richard Nixon declared in the Guam Doctrine that Asian nations should defend themselves, leading to partial troop withdrawals.
 
In 2015, while helping draft Korea-U.S. combined operational plans, I realized how difficult it was to reflect Korea’s strategic preferences in key planning documents. That frustration still resonates.
 
Korea may have to accept a redefined role for USFK, perhaps even accelerated Opcon transfer. This issue was a major focus during my tenure as chairman of the Joint Chiefs of Staff. The Roh Moo-hyun administration initially aimed for a time-based transfer in 2012, but in 2014, the two allies agreed to shift to a condition-based approach. The three key conditions were: adequate military capabilities for combined defense, comprehensive allied capability to counter North Korean nuclear threats and a stable regional security environment. None of these conditions are easily met.
 

 
In April, Joint Chiefs Chairman Dan Caine told a congressional hearing that Korea still had not met these standards, implying that Seoul’s defense capabilities remain insufficient.
 
Still, Korea cannot afford to rely on the United States alone. As threats mount, Seoul must prepare for contingencies where U.S. support may be limited. The time has come to ready our own defenses — if not with teeth, then with gums.

Translated from the JoongAng Ilbo using generative AI and edited by Korea JoongAng Daily staff.