When Gen. Xavier Brunson, commander of the United States Forces in Korea (USFK), in May identified South Korea as an "island or like a fixed aircraft carrier floating in the water between Japan and mainland China," security watchers noted the implications for a possible flexible redeployment of the USFK in other regions. However, comments recently made by Lt. Gen. Stephen Jost of the United States Forces in Japan (USFJ) went further.
In a contribution made to a Japanese daily newspaper, The Asahi Shimbun, Jost said, while stressing more cooperation with the Japanese Defense Forces, that the USFJ's primary task would shift from "alliance management missions" to "operations that span the spectrum of operations from humanitarian assistance, disaster relief and armed conflict" over time. He referred to an expanded role for the USFJ in countering China's threat in the Indo-Pacific region, writing, "The security, freedom and prosperity in the Indo-Pacific face increasing challenges from adversarial nations, primarily the People's Republic of China ... These threats are only intensifying."
In tandem, local media has reported that the USFK was using a training map of the Asian region drawn upside down to illustrate the proximity of Korea to Taiwan and the Philippines, suggesting U.S. forces possibly being deployed, should a conflict arise centered on Taiwan or in the South China Sea. Gen. Brunson is expected to meet the Korean press this month to speak about the "strategic flexibility" of U.S. forces in Korea.
The combination of these comments signals that the Trump administration's claims of strategic flexibility may materialize in not only deployment of U.S. forces in South Korea to other areas, but also a changed status for USFK command. Many eyes are watching the forthcoming U.S. National Defense Strategy, which will detail the U.S. administration's defense posture globally as competition with China deepens. Additionally, there are reports that have some officials within the Trump administration proposing to elevate the commander of the USFJ to a four-star general level while demoting the status of the current USFK commander to a three-star general's post.
To be sure, the USFJ has about 55,000 soldiers stationed in Japan and is considered a strategic command for Indo-China as well as bilaterally, while the USFK has 28,500 forces in South Korea. However, joint operations with the Japan Self-Defense Forces will not reach the capabilities of the USFK and the South Korean military anytime soon.
Korea's military alliance with the United States has long been a vital pillar in national security but also in foreign affairs. In a changing geopolitical landscape, alliances can and must adapt, but any new alliance structure should reflect new strategic realities without sacrificing credibility.
In that vein, we do not see an imminent need to demote the status of the USFK commander, who is also the commander of United Nations Command and the Combined Forces Command. Alliances that have endured layers of time should be respected and committed, even as new security challenges rise.
South Korea does not refute the need for strategic flexibility, but its strategic asset value in terms of military capability and economic prowess should be noted.
The potential looming security schisms should prompt the South Korean government to take action and review its goals, if necessary. Unlike Japan, whose prime minister has had a summit with the U.S. president and hosted U.S. Defense Secretary Pete Hegseth in March, the Lee administration has yet to do either. The presidential office said that it is working for a Lee-Trump summit soon, around late July or early August, so they should find ways to expedite it. The Lee government's stated agenda of reclaiming wartime operational control must be coldly assessed in terms of national interest, should it occur while the presence of the U.S. forces decreases.