U.S. flexibility must not weaken deterrence on North Korea

Gen. Xavier Brunson, commander of U.S. Forces Korea, said the troops “must be able to move elsewhere at any time to take on other missions.” He also pointed out that “no agreement in the U.S.-Korea alliance specifies a particular hostile force,” highlighting a shift from the long-held view of North Korea as the shared primary threat. He added that Washington is asking Seoul to assume greater responsibility for addressing the North so U.S. forces in Korea can focus on other assignments. His comments formalized plans to carry out the “strategic flexibility” concept, which would redirect the role of U.S. troops in Korea toward deterring China.

Brunson’s remarks at an official press conference signal a potential turning point for the U.S. troop presence in Korea, which has seen little change since the allies agreed to the strategic flexibility principle in 2006. Coming just two weeks before the planned Korea-U.S. summit on the 25th, they indicate the issue will likely be a major agenda item.

The restructuring of U.S. Forces Korea is part of Washington’s global strategy to make countering China the military’s top priority while expecting allies to bear more of their own security burden. In practice, it is difficult for Seoul to demand an exception. Still, South Korea cannot allow unilateral U.S. decisions that might draw it into a military conflict between Washington and Beijing. Brunson’s statement that there are “no restrictions” on the movement of U.S. forces in Korea can be interpreted as meaning they could be deployed to Taiwan in a crisis without Seoul’s consent. When the two countries agreed to strategic flexibility 19 years ago, they made clear that “South Korea will not be involved in regional conflicts in Northeast Asia against the will of the Korean people.” The current talks must adhere to that principle.

The realignment of U.S. troops must also avoid creating any opening for a weakening of deterrence against the North. Brunson said that “capability, not numbers, matters” for U.S. forces, but the change must be managed so it is not perceived as the start of troop reductions. Last year, Korea-U.S. military exercises included scenarios for responding to a North Korean nuclear attack, underscoring the central role of U.S. forces in deterring the North. Washington must not send Pyongyang any false signal that the nuclear umbrella has gaps.

Although the security environment on the peninsula is changing, the primary threat to South Korea remains North Korea. Brunson cautioned that “taking shortcuts to accelerate the transfer of wartime operational control would jeopardize military readiness on the Korean Peninsula.” Seoul should begin preparing for the long-term goal of leading the Combined Forces Command, based on increased defense spending and full readiness tied to the transition of operational control. Even then, the guiding principle in operating the alliance must be to prevent any erosion of deterrence against the North.