I had allowed myself to be deceived into unknowingly passing along a falsehood. It would ultimately prove fatal to my ability to serve the President effectively. I didn't learn that what I'd said was untrue until the media began to figure it out almost two years later. … Neither, I believe, did President Bush. he too had been deceived, and therefore became unwittingly involved in deceiving me. But the top White House officials who know the truth — including Rove, Libby, and possibly Vice President Cheney — allowed me, even encouraged me, to repeat a lie.

Bush press secretary Scott McClellan, on the illegal outing of CIA agent Valerie Plame by White House officials, What Happened; Politico.com