Joby Warrick and Walter Pincus have the scoop on how those six nuclear warheads went missing. One mistake at the beginning enabled a chain reaction that allowed the warheads to be out of custody for 36 hours:
A munitions custodian officer is supposed to keep track of the nuclear warheads. In the case of cruise missiles, a stamp-size window on the missile’s frame allows workers to peer inside to check whether the warheads within are silver. In many cases, a red ribbon or marker attached to the missile serves as an additional warning. Finally, before the missiles are moved, two-man teams are supposed to look at check sheets, bar codes and serial numbers denoting whether the missiles are armed.
Why the warheads were not noticed in this case is not publicly known. But once the missiles were certified as unarmed, a requirement for unique security precautions when nuclear warheads are moved — such as the presence of specially armed security police, the approval of a senior base commander and a special tracking system — evaporated.
Unfortunately, the Air Force investigation seems to be emphasizing individual mistakes if the airman, rather than the overall posture that puts nuclear weapons on missiles, and stores them in bunkers near bombers.