Fitzgerald: Libby knew that Plame's status was classified

It turns out that Patrick Fitzgerald is planning to prove that Scooter Libby knew Valerie Plame's status as a CIA agent was classified at the time he leaked it.

The classified status of the identity of former CIA officer Valerie Plame will be a key element in any trial of I. Lewis "Scooter" Libby, Vice President Cheney's former chief of staff, according to special counsel Patrick J. Fitzgerald.

Fitzgerald has said that at trial he plans to show that Libby knew Plame's employment at the CIA was classified and that he lied to the grand jury when he said he had learned from NBC News's Tim Russert that Plame, the wife of former ambassador Joseph C. Wilson IV, worked for the agency.

That seems to me to raise the question why, then, isn't Fitz charging Libby with the actual leaking of Plame's identity? Wasn't this the very thing he was charged to do? Or am I missing something?

It seems to me that if you were afraid the government might step in to stop the trial by refusing to release documents or by invoking the State Secrets Act, they could do that anyway if you're trying to prove Plame was an undercover agent. Bush could just say that revealing anything more about Plame's status would reveal State Secrets to the enemy and, thus, stop the trial in its tracks.