Looking Glass is the code name for an emergency airborne command post maintained by SAC (and after its demise, STRATCOM) as part of the U.S. C3I system in case of nuclear war. For twenty-five-plus years, there was always a command aircraft in flight over the U.S. or Pacific carrying a general officer from SAC and an operations staff. In the event of nuclear decapitation, this general (also referred to as Looking Glass) would assume command of U.S. nuclear forces. Elaborate systems of command and control existed (and still do, in many cases) to ensure that communications between Looking Glass (or other parts of the NCA) and the nuclear forces would remain open. Looking Glass still exists, but is no longer on 24-hour airborne alert; in the event of rising tensions or crisis, the aircraft would begin flying again.