Cheney said “the ultimate threat to the country” is “a 9/11-type event where the terrorists are armed with something much more dangerous than an airline ticket and a box cutter – a nuclear weapon or a biological agent of some kind” that is deployed in the middle of an American city.

“That’s the one that would involve the deaths of perhaps hundreds of thousands of people, and the one you have to spend a hell of a lot of time guarding against,” he said.

“I think there’s a high probability of such an attempt. Whether or not they can pull it off depends whether or not we keep in place policies that have allowed us to defeat all further attempts, since 9/11, to launch mass-casualty attacks against the United States.”…

“If you release the hard-core al Qaeda terrorists that are held at Guantanamo, I think they go back into the business of trying to kill more Americans and mount further mass-casualty attacks,” he said. “If you turn ’em loose and they go kill more Americans, who’s responsible for that?”