Angler, By Barton Gellman

Whatever the outcome of the race for the White House next Tuesday, you can be certain of one thing: the successor of President George W Bush will restore the country's battered international standing and its reputation as a law-based state.

Both Barack Obama and John McCain have repudiated some of the most controversial and shameful decisions of the Bush presidency. They are both on record in calling for the closure of Guantánamo Bay, the symbol of the worst excesses of Bush's global war on terror, and will no longer tolerate the torture of prisoners which cast a pall over America's claim to lead the "free" world.

As Bush's deputy limps off the stage, a reviled and ridiculed figure in failing health, Barton Gellman's book on "the shadow presidency of Dick Cheney" explains how he came to be the most powerful vice president in US history, and why this must never happen again.

Gellman has an impressive track record as an investigative reporter with the Washington Post. In Angler – for which Cheney declined to be interviewed – he examines how the VP took on unprecedented powers. Cheney was the one laying down the law on national security, global warming denial and energy. He was the architect of the most sweeping domestic surveillance of US citizens ever attempted, the exact scope of which remains unknown. He shut down negotiations with North Korea and brought war to Iraq. And to cap it all, he boasted, he could not be fired. "In Cheney's most productive years, he made big things happen."

Cheney hijacked the president's agenda from the moment the transition began, naming key advisers and colleagues to positions of power, including other prominent neoconservatives such as Paul Wolfowitz. But the vice president came into his own after the 9/11 attacks, which sent him scurrying for the first time into his bunker. It was then that he predicted that "We have to work the dark side, if you will. We're going to spend time in the shadows in the intelligence world."

His guiding principle was UNODIR – military shorthand for "unless otherwise directed" - which he exploited to stake out decisions of great national import without explicit authority from his boss. According to Gellman, it was Cheney himself, not President Bush, who gave the order to fire on hijacked civilian planes on 9/11.

With the president at war, Cheney's lawyers made the case for illegal practices such as "waterboarding" to be used on terror suspects. Although Gellman does not say so explicitly, it seems to me that many of this book's pages contain information that could be used to bolster a prosecution case for war crimes charges.

Cheney, whose secret service nickname "Angler" gives the book its title, took Theodore Roosevelt's maxim "speak softly and carry a big stick: you will go far", and applied it to himself. The quietly spoken Cheney used this

to such effect that his silent, expressionless stare terrified subordinates. In the course of Bush's second term, in which a fightback was mounted from within the administration against the Cheney model, the vice president's power was challenged, and he became the butt of jokes over his "dark side".

He seems to have relished his reputation for secrecy and the dark arts, joking on television that his nickname could have been "Darth Vader". But after a hunting accident in 2006 in which a friend was dispatched to hospital after being shot by Cheney during a quail hunt, the jokes came thicker and faster.

Donald Rumsfeld, the vice president's neo-con alter ego, only has a walk-on part in this book, which began as a series of Washington Post articles for which Gellman and his co-author won a Pulitzer prize. The most fascinating chapters concern Guantánamo and the domestic terror laws, covering much the same territory as another recent book on the vice president: The Dark Side by the New Yorker journalist Jane Mayer.

Waterboarding is torture. Torture is illegal. No ifs or buts. Both Gellman and Mayer identify the lawyers and White House aides who laid the legal groundwork to stretch the Geneva conventions until they snapped. We shall soon find out how squeamish the next US administration is about punishing those who stained the honour of their country by straying into the "dark side".

Anne Penketh is diplomatic editor of 'The Independent'