Seoul: A new U.S. defense strategy has indicated a potential adjustment to U.S. military presence in South Korea, increasing pressure on the Asian ally to enhance its conventional defense capabilities against North Korean threats. This development comes as Washington aims to prioritize deterring China, analysts shared over the weekend.
According to Yonhap News Agency, the Pentagon released the 2026 National Defense Strategy (NDS) on Friday. The document suggests that South Korea is poised to take "primary" responsibility for deterring North Korea, with the U.S. providing "critical, but more limited" support. This shift aligns with the U.S.'s interest in revising its military posture on the Korean Peninsula, reflecting President Donald Trump's America First policy, which encourages allies to assume greater responsibility for their own defense. This strategy coincides with President Lee Jae Myung's efforts to strengthen South Korea's independent defense capabilities and regain wartime operational control (OPCON) from the United States.
"This signals a shift in U.S. strategic focus, which requires a recalibration of responsibilities within the alliance. Under this new division of labor, South Korea will step up and bolster its national defense capabilities to take the lead in addressing North Korea's conventional threats," explained Ellen Kim, director of academic affairs at the Korea Economic Institute of Korea, to Yonhap News Agency. She added that the U.S. would concentrate on providing crucial strategic assets to assist South Korea in countering North Korea's nuclear and WMD threats.
The NDS's reference to "critical" U.S. support underscores America's commitment to employing its nuclear arsenal as part of its "extended deterrence" for South Korea, which now has a conventional defense advantage over the North's aging military equipment. Last year, the Trump administration reaffirmed its commitment to providing extended deterrence through a joint fact sheet outlining bilateral security and trade agreements.
Nam Chang-hee, an international politics professor at Inha University, noted, "The NDS indicates that it would guarantee the nuclear umbrella while South Korea undertakes the conventional capability part to deal with North Korea." He further mentioned that if the nuclear umbrella commitment falters, South Korea might consider either developing its nuclear weapons or significantly increasing its conventional forces.
The NDS also aims to "upgrade" the U.S. force posture in Korea, amidst speculation about potential changes in the mission, operational scope, and composition of the 28,500-strong U.S. Forces Korea (USFK). The discussions between Seoul and Washington regarding "alliance modernization" have pointed towards a possible shift in USFK's role to address regional crises, including those involving Taiwan.
Ellen Kim remarked on the potential for greater flexibility in the USFK force posture, which might involve relocating U.S. forces based on strategic priorities. Some experts suggest the U.S. could reduce the Army's role within the USFK while increasing the presence of the Air Force and Navy, optimizing the force configuration for China-related contingencies.
Nam indicated that the NDS appears to document the U.S. shift towards focusing the USFK on the Taiwan issue rather than solely on the defense of the Korean Peninsula. He emphasized that the U.S. is primarily interested in curbing China's rise, beyond just preventing an attack on Taiwan, while South Korea is increasingly capable of maintaining deterrence against North Korea.
The NDS's call for South Korea to assume primary defense responsibility aligns with the Lee administration's goal to regain wartime OPCON by 2030. The allies have been working towards a "conditions-based" OPCON transition, involving South Korea's capability to lead combined forces, its strike and air defense capacities, and a conducive regional security environment.
"The Trump administration's call for a balance of responsibility within the alliance creates a favorable environment for revisiting wartime operation control issues," Kim commented.
Throughout the NDS's development, questions persisted about whether it would include the objective of North Korea's denuclearization, a goal Trump has pursued. The 2026 NDS, like its 2022 predecessor, does not mention denuclearization. The National Security Strategy (NSS), released in December, similarly omits this objective.
Nam speculated that the absence of the denuclearization goal might allow Trump to retain leverage as he prepares to resume talks with North Korean leader Kim Jong-un during an upcoming summit with Chinese President Xi Jinping. Kim suggested that the delay in addressing denuclearization in U.S. strategic documents could be due to internal disagreements or political indecision, leaving room for dialogue with Pyongyang.
Trump's desire to reengage with Kim has been evident since his first term, during which he held three summits with the North Korean leader. In May, the Pentagon tasked Under Secretary of Defense for Policy Elbridge Colby with drafting a new NDS to prioritize burden-sharing with allies and deterring China in the Indo-Pacific, preceding Colby's reported visits to South Korea and Japan.
The NDS outlines the Pentagon's defense objectives and policy direction in line with the NSS.