On Thursday, Richard Armitage went on CBS News and confessed: he was the original source for the Robert Novak column that outed Valerie Wilson as a CIA officer. He apologized to Valerie and Joseph Wilson. In an interview with The New York Times, Armitage said, “It was a terrible error on my part. There wasn’t a day when I didn’t feel like I had let down the president, the secretary of state, my colleagues, my family and the Wilsons. I value my ability to keep state secrets. This was bad, and I really felt badly about this.”

Armitage is coming forward now because the book I co-wrote with Michael Isikoff of Newsweek, HUBRIS: The Inside Story of Spin, Scandal, and the Selling of the Iraq War, disclosed Armitage’s role and quoted named sources at the State Department confirming Armitage’s role as the leaker. Armitage says that he kept his silence all these years because special prosecutor Patrick Fitzgerald had asked him not to say anything. But after our book triggered a splash of news reports, Armitage asked Fitzgerald if he could go public, and he obtained Fitzgerald’s consent.

Which brings me to a rather simple question: When will Karl Rove do the same?

He is no longer under investigation. But he did play a critical role in the leak case by confirming Armitage’s information for Novak and then (before the Novak column appeared) leaking the same classified information to Matt Cooper of Time, as part of a campaign to discredit Joseph Wilson. (Hubris–which chronicles the behind-the-scenes battles in the CIA, the White House and Congress in the run-up to the war–has new details on Rove and Scooter Libby’s efforts to undermine Wilson.) So will Rove now explain precisely what he did and why he did it, as Armitage has? Is he willing to admit he mishandled state secrets? Is he also sorry? Will he apologize to anyone?

Once upon a time, President Bush said he wanted the truth about the leak to come out. Libby, who is facing indictment for having allegedly lied to FBI agents and a grand jury about his involvement in the leak episode, may feel he is in no position to emulate Armitage. But Rove is not so encumbered.

What reason might Rove have for not following Armitage’s lead?