The proximate trigger of Gates' decision to ask for these resignations was a report on the circumstances that led up a B-52 carrying six nuclear-tipped missiles under its wings on a flight down the length of the United States last summer—without the bomber's crew even realizing the missiles had warheads. (Fortunately, the warheads weren't live, so there was no danger of a nuclear explosion, even if the B-52 had crashed.) The post-mortem—following an inquiry handled by a Navy admiral—remains unpublished. But it is widely said to be "scathing" (as one civilian official, who requested anonymity discussing sensitive matters, put it) about the sloppiness of the procedures which gave rise to the incident—as well as the unruffled response from the Air Force in the face of the screw-up. The attitude seemed to be that the incident, while regrettable, reflected merely low-level failures to follow established procedures for handling nuclear weapons. (In the subsequent uproar, officials discovered more or less by chance that four Air Force ballistic missile fuses which arm the nuclear warheads had been mistakenly shipped to Taiwan in 2006—and not retrieved for 17 months.)
As it says later in the article, "Gates took a more systemic view: if the Air Force is sloppy about nuclear weapons, what isn't it sloppy about?" It's good to see that we now have an accountability-minded man in the position of Secretary of Defense. It's a pity that he wasn't there from the beginning to spare us this Rumsfeldian nightmare.