Edgewise

Cheney the prime mover behind leak

Christian Crumlish

According the special prosecutor's press release

On or about June 12, 2003, Libby was advised by the Vice President of the United States that Wilson’s wife worked at the CIA in the Counterproliferation Division. Libby understood that the Vice President had learned this information from the CIA.

So, at least as far as Libby is concerned, Cheney was the one pushing the information. Like any good crime boss, he didn't do the actual whacking himself, but he made it clear what was expected.