In short, it tells how the administration built it's anti-terrorist policies on the ravings of a disturbed mental patient -- taken off his medication and subjected to water torture.
Abu Zubaydah -- the hot shot al Qaeda "Number 2" (the first of the #2s we captured) turned out to be the travel agent for al Qaeda's wives and kept diaries written by each of his three personalities.
Abu Zubaydah -- or, let's call him "al-Sybil" for the split personality thing -- started talking under torture -- making up "targets."
The Washington Post sums up the process of getting useless information:
They strapped Abu Zubaydah to a water-board, which reproduces the agony of
drowning. They threatened him with certain death. They withheld medication. They bombarded him with deafening noise and harsh lights, depriving him of sleep. Under that duress, he began to speak of plots of every variety -- against shopping malls, banks, supermarkets, water systems, nuclear plants, apartment buildings, the Brooklyn Bridge, the Statue of Liberty. With each new tale, "thousands of uniformed men and women raced in a panic to each . . . target." And so, Suskind writes, "the United States would torture a mentally disturbed man and then leap, screaming, at every word he uttered."
The title of the book comes from the administration's theory that if there is a 1% likelihood that a rumor is true -- it should be treated as the truth. That spreads resources thin and commits them to thousands of wild goose chases.
CIA terrorist hunters say they saw their jobs as no longer looking for intel, but looking for arguments to back up the administration's policies.
There are also some good lines -- like the one about Bush brushing off a warning on the Aug 6, 2001 PDB as "All right. You've covered your ass, now."
It also details how the President ignored his top people at Tora Bora who wanted more troops committed.
President Bush relied on untrained Afghan warlords -- letting Osama slip away.