March 27, 2026
SEOUL – US Forces Korea established a dedicated unit to integrate US strategic assets into alliance military planning, multiple South Korean and US sources said, operating separately from the allies’ joint command structure.
With the unit in place, US officials involved in nuclear operations are expected to be stationed in South Korea — an extension of the allies’ commitment to strategic coordination. Some observers in Seoul, however, warn that key elements could be handled through separate channels in practice, particularly regarding nuclear assets.
According to sources familiar with the matter on Thursday, USFK has operated the J10 Strategic Integration Element since around June 2025, led by a US Army colonel.
The nomenclature follows the US military’s joint staff system, in which J10 is typically used for nuclear and countering weapons of mass destruction functions, while other designations denote functional areas such as J1 for personnel, J2 for intelligence and J3 for operations.
The unit was originally formed under J5 for planning in 2024, a source familiar with US military affairs said. J10 now leads bilateral conventional-nuclear integration efforts within the alliance and serves as a hub for nuclear deterrence expertise within USFK, the source added.
A separate source in South Korea said that the J10 unit also serves in part as a liaison between USFK and US Strategic Command, which oversees the United States’ nuclear arsenal and other strategic capabilities.
USFK confirmed the existence of the unit, but declined to comment further. The unit has not yet been publicly listed on the USFK website.
Shift in strategy
The establishment of a dedicated strategic deterrence unit within USFK suggests that Washington may be shifting some strategic planning authority to a separate US-managed channel.
Although nuclear weapons remain under exclusive US control under US Strategic Command, such planning has traditionally been handled within the allies’ Combined Forces Command, the US-led wartime operational command on the Korean Peninsula.
The CFC is commanded by a US four-star general, who also serves as USFK commander, while a South Korean four-star general serves as deputy commander.
At the CFC, nuclear-related planning has been carried out through a combined structure, with personnel from both sides taking part, including experts from South Korea’s Joint Chiefs of Staff and USFK.
This framework has allowed close coordination on sensitive military planning, including responses to nuclear threats. However, observers say the move could reshape the structure of nuclear-related planning within the alliance.
Yoo In-seok, a professor of military studies at Yeungnam University, said the change could affect how such planning is structured between Seoul and Washington.
“While nuclear assets remain under US control, what matters is how they are incorporated into operational scenarios,” Yoo said.
“The establishment of an independent unit within USFK means key elements of that planning process can be handled within USFK first, before being shared with the combined framework,” he added.
“This could reduce South Korea’s role in the early stages of planning, shifting the structure from joint design to a model where US-developed options are later integrated.”
Yoo is a retired Army colonel who previously headed the Joint Chiefs of Staff’s nuclear and weapons of mass destruction response planning division.
Concerns in Seoul
In Seoul, the move potentially raises concerns about the allies’ consultation mechanisms that underpin the US extended deterrence framework.
In April 2023, Seoul and Washington issued the Washington Declaration, under which Seoul reaffirmed its commitment not to pursue its own nuclear armament, while Washington pledged to strengthen extended deterrence and expand consultation on nuclear planning — a reaffirmation of their long-standing security arrangement amid growing North Korean nuclear threats.
As part of the agreement, the allies established the Nuclear Consultative Group, a high-level mechanism involving defense, diplomatic and intelligence authorities from both sides, including USFK, the CFC and the Joint Chiefs of Staff of both countries, to strengthen joint consultation on nuclear deterrence.
Retired Col. Yoo said the emergence of a separate operational channel could raise questions about how such joint consultation would function in practice.
“Despite North Korea’s advancing nuclear threats, South Korea has refrained from pursuing its own nuclear armament, relying instead on US extended deterrence,” Yoo added.
“While this could be seen as a practical step to strengthen policy-level coordination through mechanisms like the NCG, if operational matters are handled through separate channels, it could undermine the spirit of such arrangements.”
Linked to OPCON shift?
Some observers link the move to Seoul’s efforts to expand its role in the strategic domain.
South Korea elevated its nuclear and WMD response unit within the Joint Chiefs of Staff in 2023. The following year, it expanded into a Strategic Command to oversee missile forces and counter-WMD operations.
These steps are widely seen as part of preparations for the transfer of wartime operational control from Washington to Seoul — a goal South Korea aims to achieve by 2030.
Under the current plan, a South Korean general is expected to take over command of the Combined Forces Command once wartime operational control is transferred, with some in Seoul viewing the Strategic Command chief as a potential candidate.
“There are also views in Seoul that Washington may have taken a series of steps out of concern that, once wartime operational control is transferred, a South Korean general could take on a greater role within the Combined Forces Command,” a Seoul official said on condition of anonymity.
According to a separate source familiar with US military affairs, in August 2025 the J10 unit took part in the Iron Mace exercise, which is the allies’ combined tabletop exercise focused on integrating conventional and nuclear capabilities under the NCG framework.
“The J10 unit supports the NCG and works closely with South Korea’s Strategic Command,” the source added.