From Josh Marshall:
Go to page 5 of the indictment. Top of the page, item #9.
On or about June 12, 2003, LIBBY was advised by the Vice President of the United States that Wilson's wife worked at the Central Intelligence Agency in the Counterproliferation Divison. LIBBY understood that the Vice President had learned this information from the CIA.
This is a crucial piece of information. The Counterproliferation Division (CPD) is part of the CIA's Directorate of Operations, i.e., not the Directorate of Intelligence, the branch of the CIA where 'analysts' come from, but the DO, where the spies, the 'operatives', come from.
Libby's a long time national security hand. He knows exactly what CPD is and where it is. So does Cheney. They both knew. It's right there in the indictment.