The Bush line — which we have heard often — is that we learned on 9/11 how dangerous the world is. And that was why there was a marked shift in Bush’s foreign policy after 9/11.

It holds water, except for one problem: David Letterman.

In October 2000, presidential candidate George Bush appeared on Lettermen, where they had (in parts) a surprisingly serious discussion. Here’s one account:

So Letterman then asked Bush about the terrorist murder of 17 U.S. sailors in Yemen. Seriously.

"If I find out who it was, they’d pay a serious price," Bush said of the bombing. "I mean a serious price."

"Now, what does that mean?" Letterman asked, a follow-up Bush doesn’t often get when he’s asked about such bravado.

"That means they’re not going to like what happened to them," Bush said, and the crowd went wild.

"Now are you talking about retaliation or due process of law?" Letterman asked.

"Heh-heh," Bush said. "I’m talking about gettin’ the facts and lettin’ them know we don’t appreciate it and there’s a serious consequence … And I’ll decide what that consequence is."

Macho man, huh? But, in all fairness, a fitting response.

Eventually we learned . . . before Bush was even sworn in . . . that the Cole bombing was the dirty work of Osama bin Laden. But, alas, there was no "serious consequence" until after 9/11.

I raise this so that readers will keep in mind — that when Bush says that "9/11 changed things" (and he will say it), he’s blowing smoke. If Bush on the Letterman show is to be believed, he was prepared to act as soon as the facts were in. And the facts were in by the time he was "elected". And tough-talking Bush didn’t act.