Following the withdrawal of nuclear weapons from South Korea in 1991, the US military has reorganized its nuclear planning against North Korea. Nuclear strike planning in support of operation plans (OPLAN) and other contingencies has been transferred to the 4th Fighter Wing based at Seymour Johnson Air Force Base in North Carolina. In case the US president ordered the use of tactical nuclear bombs against North Korea, the 4th FW would forward deploy to the region (probably Guam) and stage long-range strikes against designated targets.
During several exercises and training in the first half of 1998, according to the 4th FW command history, the 336th Fighter Squadron of the 4 FW scrambled (“generated”) F-15E Strike Eagle fighter-bombers in a simulated nuclear strike against the North. Instead of flying to Korea, the aircraft dropped their BDU-38 dummy nuclear bombs at the Avon Park Bombing Range in Florida. The scenario was the same for all the exercises, as described by the wing commander:
“We simulated fighting a war in Korea, using a Korean scenario. This included [North Korean] chemical attacks to protect against using full chemical gear [sic]. The scenario . . . simulated a decision by the National Command Authority about considering using nuclear weapons. . . . We identified aircraft, crews, and [weapon] loaders to load up tactical nuclear weapons onto our aircraft.” The “last phase of the exercise, the employment phase . . . required us to fly those airplanes down to a range in Florida and drop” the BDU-38s.
These and other documents are described in the article “Preemptive Posturing” in the Bulletin of the Atomic Scientists. The documents in the right-hand bar provide links to documents released under FOIA about the 4th FW’s nuclear operations in 1998.
FOIA documents
>> US Air Force, “History of the 4th Fighter Wing, January-June 1998,” n.d. [1998], excerpts about simulated nuclear strike on North Korea. SECRET/NOFORN. Partially declassified and released under FOIA. [0.12 MB]
>> US Air Force, “History of the 4th Fighter Wing, January-June 1998,” n.d. [1998], nuclear excerpts. SECRET/NOFORN. Partially declassified and released under FOIA. [1.03 MB]
See also documentation on 1991 withdrawal of nuclear weapons from South Korea, and documents from the 1994 Nuclear Posture Review.
Feature article:
>> “Preemptive Posturing,” Bulletin of the Atomic Scientists, September/October 2002, pp. 54-59.
>> 
The Nation, “Endgame in Korea,” November 25, 2002, refers to “Preemptive Posturing” and 4th Fighter Wing simulated nuclear strikes against North Korea.