As I wrote yesterday in response to this article by Waas about the July 8 meeting of Libby and Miller:

I think Judith Miller is protecting her stable of Pentagon sources - not just Lewis Libby. And that range could establish the coverup and implicate those at the very top - up to or just short of Dick Cheney. I don't think a personalized waiver from Libby would have made any difference at all. What Miller would need to talk is an assurance from Fitzgerald that she will be questioned only about her meeting and conversations with Libby and that she need not reveal any other source. Or, she needs the same assurance from Fitzgerald that he gave to Walter Pincus: that she can testify to the substance of her conversations with her source but not confirm his identity.

Here's what Judith Miller said on why she won't comply:

"I felt that I didn't want to start to go down the road of testifying about someone who may or may not be a source, because, at this point, the focus of Mr. Fitzgerald's inquiry has been on one person. But, as we've seen from Matt Cooper, if you make a deal to discuss that one person who may or may not have given a voluntary waiver, what about what happens when Mr. Fitzgerald's target of interest or person of interest shifts?"

"And then there's another person and another person who comes under suspicion. And, eventually, somebody might actually get to one of your sources, if they haven't already. I just decided that the position has got to be, if I promised someone confidentiality, whether or not he was a source on a particular story, I'm not going to go in and testify about what that person told me. Otherwise, I can't do my job. "

[Source: CNN October 25, 2004,Transcript of Miller and Aaron Brown, CNN, Newsnight]

The Washington Post reported it this way:

Her position is that no such waiver under pressure from a prosecutor can ever be voluntary.

Libby's lawyer also told the New York Times that Cooper didn't get a "personalized waiver" from Libby before he agreed to be deposed by Fitzgerald about Libby:

Mr. Cooper's statements on Wednesday echoed his rationale for testifying last summer. "Mr. Libby," a statement issued by the magazine at the time said, "gave a personal waiver of confidentiality for Mr. Cooper to testify."

In an interview Friday, Mr. Libby's lawyer, Joseph A. Tate, disputed that. "Mr. Libby signed a form," Mr. Tate said. "He gave it back to the F.B.I. End of story. There was no other assurance."

Unlike Judith Miller, Matthew Cooper was looking for any way to stay out of jail and he seized on this "personalized waiver" to do it. Libby can provide all the waivers he wants to Miller. She is not going to talk - unless she's facing a criminal indictment for obstruction of justice or a criminal contempt charge after her civil confinement is up. Then she may re-think it. End of story.

Update: I just read Rep. Conyers' Huffington Post entry about his letter. I think he fell for the set-up. Look at Murray's sources for the quote about Libby and the personal waiver:

"Sources close to the investigation, and private attorneys representing clients embroiled in the federal probe, said that Libby's failure to produce a personal waiver may have played a significant role in Miller's decision not to testify about her conversations with Libby, including the one on July 8, 2003.

"Sources close to the investigation" sound like the Republican spin lawyers helping the private lawyers who represent those under investigation. (If they were representing mere witnesses, they wouldn't be "embroiled" in the probe.) As I said yesterday, this is spin from Rove and Company, and as it gets closer to October, you can expect the lawyers for those most likely to be indicted to begin playing their defense in the media. It seems like it's getting to be "each man for himself" time over at the White House, and Rove is starting the dump on Libby. No way is Rove going to allow himself to go down alone.