For those watching the quite good HBO series Rome, and seeing parallels between their tyranny-besotted republic and ours, there's a quote that you might enjoy. It wasn't specifically written about Cheney, Bush, Libby, Rove, Rummy, Perle, Wolfowitz et al. But it could have been.
A nation can survive its fools, and even the ambitious. But it cannot survive treason from within.
An enemy at the gates is less formidable, for he is known and he carries his banners openly. But the traitor moves among those within the gate freely, his sly whispers rustling through all the galleys, heard in the very hall of government itself. For the traitor appears not a traitor—he speaks in the accents familiar to his victims, and wears their face and their garment, and he appeals to the baseness that lies deep in the hearts of all men. He rots the soul of a nation—he works secretly and unknown in the night to undermine the pillars of a city—he infects the body politic so that it can no longer resist. A murderer is less to be feared.
Who said it? Cicero, in the year 42 B.C.E.
(Hat tip to commentor Salient at the Huff Post.)