IN 1993, Bill Clinton was pondering whether to authorise what is now called an “extraordinary rendition”, when American agents snatch a suspected terrorist abroad and deliver him to interrogators in a third country. The White House counsel warned that this would be illegal. President Clinton was in two minds until Al Gore walked in, laughed and said: “That's a no-brainer. Of course it's a violation of international law, that's why it's a covert action. The guy is a terrorist. Go grab his ass.”

To understand how the Bush administration went crashing off the rails, it helps to know where the train was coming from. “Law and the Long War” gives a clear and vivid account of how President George Bush and his inner circle came to adopt so many harrowing tactics in their struggle against al-Qaeda and its ilk.

A fellow of the Brookings Institution, a non-partisan think-tank, Benjamin Wittes is scrupulously fair. Doves think that America should close Guantánamo, abstain from interrogations that trouble the conscience and either try its enemies in open court or free them. Hawks think that the president has (and should have) the power to do whatever is necessary to stop a dirty bomb going off in an American city. To Mr Wittes, the right way to deal with groups such as al-Qaeda is “terrifyingly, dangerously, paralysingly non-obvious”.

Extraordinary renditions, synonymous today with Mr Bush's excesses, were quite common under Mr Clinton. But they got much uglier after September 11th 2001. The snatches became more frequent, and therefore more prone to error. Rather than simply handing terror suspects over to countries where they faced criminal charges, the CIA started interrogating them itself. Unlike Mr Gore, the Bush administration was not content to break the rules quietly from time to time. Instead, it argued that suspects could be seized and held indefinitely on the president's say-so, and subjected to “enhanced interrogation techniques” that sounded awfully like torture.

The Bush administration was appallingly negligent about abuses at Abu Ghraib. Far more alarming, however, are the abuses it authorised in cold blood. Dick Cheney promised to “work…the dark side” to defeat al-Qaeda. As Jane Mayer documents in “The Dark Side”, he meant it.

Putting a hood on someone's head does not, in itself, amount to torture. Nor, necessarily, does depriving him of light or keeping him awake when he is tired. But when such techniques are used in combination and over a long period, they add up to something cruel and unusual. Ms Mayer, a writer for the New Yorker, describes horrors in sparse prose. One suspect was shaved, force-fed, sleep-deprived, ordered to bark like a dog, hammered with ear-splitting pop music, kept in a cold room and shackled so he could not pray. He begged to be allowed to commit suicide.

For a straightforward and chilling narrative of where Mr Bush erred, Ms Mayer's book is the easier read. But Mr Wittes's analysis is more subtle, and he tries harder to offer solutions. Neither the laws of war nor ordinary criminal laws are suited for the struggle against al-Qaeda, he says. America needs a new, hybrid set of rules.

Mr Bush should have asked Congress to write such rules. Had he done so, he would have received nearly all the powers he wanted, and he would have been seen to act legally. The worst abuses might never have happened, and America would not have seen its reputation for lawfulness dragged through the sewers. Instead, Congress has left it largely to the courts to check the executive; they can do so piecemeal, but it is plainly beyond their competence to devise a whole new set of rules.

Congress has not been wholly idle. Thanks in part to John McCain, the law governing military interrogations has been tightened. But the CIA still uses interrogation tactics that Mr Bush will not name, and Mr Cheney still insists that the decision to use water-boarding (simulated drowning) was a “no-brainer”. By flaunting its contempt for international norms, the administration renders those norms laughing-stocks, laments Mr Wittes.