n February 2003, Secretary of State Colin Powell, addressing the UN Security Council, ... many people in the political and media establishments swooned: They admired Powell, and because he said it, they believed it.

Powell's masters got the war they wanted, and it soon became apparent that none of his assertions had been true.
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The administration, this time relying on General David Petraeus to play the Colin Powell role, has had remarkable success creating the perception that the "surge" is succeeding, even though there's not a shred of verifiable evidence to suggest that it is.
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But, say the usual suspects, Petraeus is a fine, upstanding officer who wouldn't participate in a campaign of deception - apparently forgetting that they said the same thing about Powell.

First of all, Petraeus is now identified with the surge; if it fails, he fails. He has every incentive to find a way to keep it going, in the hope that somehow he can pull off something he can call success.