Here's a question. If I understand this right, Scooter Libby has sworn under oath that Vice President Cheney told him that President Bush had authorized him to disclose classified information.

Let's set aside the whole question of whether the president can do that or whether there's a specific procedure he has to follow. Just set that issue aside.

If it isn't true that Vice President Cheney told him that, then Vice President Cheney must know that Libby has again perjured himself. I would think the Vice President has an affirmative duty to come forward and say that Libby's testimony is false.

I just overheard Jeff Toobin on CNN saying that the White House will probably be able to squelch this story simply by 'no commenting' it. But can we not fairly draw the inference from Cheney's silence that he did in fact tell Libby this?

By a slightly looser logic -- and one in which sworn testimony doesn't come into play in the same fashion -- doesn't President Bush's silence tell us that Cheney was telling the truth?