Which of the following is not listed as an Air Force contribution to nuclear operations?

The correct answer, attack helicopters, are not typically recognized as a significant contribution to nuclear operations. In the context of the Air Force's role in nuclear operations, the focus primarily lies on capabilities that deliver nuclear weapons or support strategic deterrence.

Fighter jets, missile submarines, and nuclear bombers are all integral to nuclear operations. Fighter jets can perform quick-response missions to deliver nuclear payloads if necessary, while nuclear bombers are specifically designed to carry and deploy nuclear weapons on long-range missions. Missile submarines also play a vital role in nuclear deterrence through their ability to launch ballistic missiles from sea, providing a secure second-strike capability.

In contrast, attack helicopters are primarily designed for tactical ground support and are generally not equipped for nuclear operations. While they are vital for many military operations, including close air support and anti-armor missions, they do not have a direct role in the strategic nuclear posture of the Air Force. Thus, recognizing the specific capabilities and roles of each type of aircraft in nuclear operations clarifies why attack helicopters are not included in the list of contributions.