The Dark Side, Jane Mayer's gripping new account of the war on terror, is really the story of two wars: the far-flung battle against Islamic radicalism, and the bitter, closed-doors domestic struggle over whether the president should have limitless power to wage it. The war on terror, according to Ms. Mayer, ... was a "political battle cloaked in legal strategy, an ideological trench war" waged by a small group of true believers whose expansive views of executive power she traces from the Nixon administration through the Iran-contra scandal to the panicked days after 9/11. Ms. Mayer's prime movers and main villains are Vice President Dick Cheney and his legal counsel (now chief of staff) David Addington, who after the terrorist attacks moved to establish "a policy of deliberate cruelty that would've been unthinkable on Sept. 10." As the leader of the self-styled "war council," a group of lawyers who took the lead in making the rules for the war on terror, Mr. Addington startled many colleagues with the depth of his fervor and the reach of his power. The war council settled on a "pre-emptive criminal model," in which suspects would be used - more or less indefinitely - to gather evidence of future crimes rather than held accountable for previous ones. There would be minimal oversight from Congress. The C.I.A. would take the lead, developing aggressive new interrogation methods that would be described as "enhanced," "robust," "special." What they were not, a series of secret memos issued by John Yoo and others at the Office of Legal Council would attempt to certify, was "torture."