His former wife, Valerie Plame, was a CIA "operative" who specialized in WMDs. She was 'outed' in a newspaper column by Robert Novak on 14 July 2003.

This led to a Justice Department investigation into possible violation of U.S. criminal law regarding exposure of covert government agents. Disclosing the identity of undercover intelligence operatives is a felony punishable up to 10 years in prison.

It appears now, from documentary evidence, that Karl Rove (Deput Chief of Staff) leaked the information about Valerie Plame/Wilson.
The administration had repeatedly said in the past that anyone who leaked this information would be fired. The backpedalling that is now going on concerning this statement suggests that they were not expecting to be found out.

Karl Rove is the Deputy Chief of Staff and advisor to the President of the United States. Operationally, he is third in command of the government. He carries the diplomatic rank of a three star general. He has served former President Bush and Gov. William Clements in addition to teaching Journalism, Public Affairs and would undoubtedly have served in a high profile position politically in the nineties if the Republicans had controlled the Whitehouse.

He is intelligent and politically savvy. My point is, he is not some bumpkin off the street that makes rookie mistakes. He leaked to Valerie Plame's information to the press in reprisal for the Ambassador's accusations (which turned out to be true) that embarrassed the Whitehouse.

Do you really think that there is even the slightest possibility that he would have done this without implied consent from the President?