Let’s say you’re a federal prosecutor.       

You’re investigating officials in the Bush White House, trying to find out whether they violated the Intelligence Identities Protection Act or the Espionage Act when they told reporters that Valerie Wilson, wife of the ardent Bush critic Joseph Wilson, worked for the CIA.

Violations of those laws would be a very serious matter indeed. And just to make your investigation a high-pressure affair, you’re dealing with some very prominent figures, including Lewis Libby, the vice president’s chief of staff, and Karl Rove, the president’s top political adviser.

Then you run into a problem. You look and look, but you can’t find enough evidence to charge either man — or anyone else — with breaking the two big national-security laws.

But you believe you have a good case that Libby lied to your grand jury. So after more than two years of probing, you charge him with perjury, obstruction of justice and making false statements.

So here’s the question: In preparation for trial, Libby’s defense lawyers want you to give them evidence that when you began the investigation you had a good reason to believe that a crime had been committed — that is, that someone had violated the intelligence identities law or the Espionage Act. Do you give it to them?

First, they want you to turn over documents showing that Valerie Wilson was a covert agent for the CIA at the time she was outed in Robert Novak’s column on July 14, 2003.

Then they want the documents showing that Mrs. Wilson had been covert at some point in the five years before she was mentioned in the Novak column — a key requirement for prosecution under the intelligence identities law.

And then they want documents outlining the damage Mrs. Wilson’s unmasking has done to national security.

At least to an outsider, those might seem like reasonable requests. After all, that’s why you started your investigation, wasn’t it?

So what do you say?

Fuhggedaboudit.

The following is from recent correspondence between CIA leak prosecutor Patrick Fitzgerald and the Libby defense team:

On Dec. 14, 2005, Libby’s lawyers asked for “all documents, regardless of when created, relating to whether Valerie Wilson’s status as a CIA employee, or any aspect of that status, was classified at any time between May 6, 2003, and July 14, 2003.”

To which Fitzgerald replied, on Jan. 9, “We have neither sought, much less obtained, ‘all documents, regardless of when created, relating to whether Valerie Wilson’s status as a CIA employee, or any aspect of that status, was classified at any time between May 6, 2003, and July 14, 2003.’”

Then the Libby lawyers asked for “any assessment done of the damage (if any) caused by the disclosure of Valerie Wilson’s status as a CIA employee.”

To which Fitzgerald replied, also on Jan. 9, “A formal assessment has not been done of the damage caused by the disclosure of Valerie Wilson’s status as a CIA employee, and thus we possess no such document.” And by the way, Fitzgerald added, we wouldn’t view that information as relevant to your case, so you can forget about getting it.

About the issue of whether Mrs. Wilson had been undercover in the five years before the Novak article, Fitzgerald said, in effect, we might have some proof of that — or we might not. You don’t need to know.

In each instance, Fitzgerald told the Libby lawyers that their requests for information on any underlying crime were irrelevant because Libby is charged with lying under oath, not with violating the Intelligence Identities Protection Act or the Espionage Act.

Well, yes, but that’s not the whole story, say Libby’s attorneys. Just look, for example, at the question of damage to national security.

“Potential harm to national security was a focus of the government’s investigation,” Libby’s team wrote in a Jan. 31 brief. “In fact, the indictment alleges that disclosure of the fact that individuals such as Ms. Wilson ‘were employed by the CIA had the potential to damage the national security.’”

The Libby team went on to point out that in his news conference last October, Fitzgerald said the leak of Mrs. Wilson’s name was not only harmful, that “the damage wasn’t to one person. It wasn’t just Valerie Wilson. It was done to all of us.”

But now, Fitzgerald maintains that the most fundamental information in the case — was an underlying crime actually committed? — is not important.

Maybe he’s on solid legal grounds. Maybe not. We’ll find out later this month, when the issue is argued in court.

But for those of us outside the courtroom, for those of us who have been told for years that the leak of Valerie Wilson’s name was a very serious crime, wouldn’t it be a good thing to know whether or not that was true?

York is a White House correspondent for National Review. His column appears in The Hill each week. E-mail: This email address is being protected from spam bots, you need Javascript enabled to view it