The Dogs That Didn't Bark - Why Colin Powell and George Tenet aren't bashing Richard Clarke:

"In the short story 'Silver Blaze,' Sherlock Holmes solves the mystery of a stolen racehorse by observing that the stable's guard dog didn't bark—hence, the intruder was not a stranger.

The mystery of whether Richard Clarke is telling the truth about President Bush's counterterrorism policies might be solved the same way: Which dogs aren't barking? Amid all the administration officials bombarding the airwaves with denunciations, who has stayed mum?

The answer: Secretary of State Colin Powell and CIA Director George Tenet, and their silence speaks loudly."