Following the ending of the Cold War and the withdrawal of nuclear weapons from South Korea, US planning has continued for nuclear strike missions against North Korea.
Delivery of non-strategic bombs is now the responsibility of fighter wings based in the continental United States. In 1998, for example, F-15E fighter bombers of the 4th Fighter Wing at Seymour Johnson Air Force Base in North Carolina simulated long-range nuclear strikes against North Korea. Strategic nuclear systems earmarked for Korean scenarios include Trident submarines and long-range bombers.
Missile defense planning on the Korean Peninsula, moreover, suggests a US posture that is highly focused on a need for preemptive strikes against North Korean ballistic missile facilities in the early phases of a war with the North.
These issues, for which background documents are available in the right-hand bar, are described more in the article “Preemptive Posturing” from the September/October 2002 issue of the Bulletin of the Atomic Scientists.
FOIA Documents
>> 4th Fighter Wing simulated nuclear strike against North Korea, 1998.
>> 1994 Nuclear Posture Reviewdiscussion of impact of forward deployment of nuclear weapons in South Korea. General NPR documents available here.
>> 7th Air Force, briefing, “Theater Missile Defense,” n.d. [1998] (warning: 8.5 MB).
>> 
The Nation, “Endgame in Korea,” November 25, 2002, refers to “Preemptive Posturing” and 4th Fighter Wing simulated nuclear strikes against North Korea.
>> Article: Hans M. Kristensen, “Preemptive Posturing,” Bulletin of the Atomic Scientists, September/October 2002, pp. 54-59.