Considering How Easily the Plot Was "Foiled",

I vote for "idle daydream":

The intelligence officials, who declined to be identified because they did not want to criticize the White House publicly, said there is deep disagreement within the intelligence community over the seriousness of the scheme to attack the 73-story building and whether it was ever much more than talk.

Bruce Hoffman, a terrorism specialist with the Rand Corp., said Bush's account still leaves key questions unanswered.

"It doesn't really give us any more indication of whether this was a plot that was derailed or pre-empted, or a plot that was more in the realm of an idle daydream," Hoffman said.