Colin Powell, Armitage’s boss, knew for THREE YEARS that Armitage was the leaker, and kept his mouth shut, while Libby and Rove almost went to prison.
My understanding at the time was that Plame’s own husband revealed her identity. It’s not worth my time here to dig up old links, but that was my impression at the time. Scooter was simply the “face saving offering” to finish it and move on.