On 20 January 2001, George W Bush swore the oath of office as the 43rd president of the United States, vowing to support and defend the constitution "against all enemies, foreign and domestic". He has acquired millions of both. Among the most dangerous are people who worked for him who now want to tell their story.

Richard Clarke's account is the most devastating yet. This is a man who served four presidents over more than a decade. Clarke's allegation that Bush and the neoconservatives ignored the al-Qaeda threat as they pursued their obsessions with Iraq has, in election year, wounded the White House deeply.

But his is a broader narrative of the world of terrorism and intelligence, taking us from the Soviet Union to Afghanistan, Saudi Arabia, Sudan, Somalia, the Tokyo underground nerve gas attacks, the Oklahoma bombing and the two Gulf wars. He takes us through the various attacks on US targets well before 9/11 and describes the emergence of a man "whose name kept appearing buried in the CIA's raw reporting as 'terrorist financier Osama Bin Laden'". It took several years for the intelligence community in Washington to appreciate the danger Bin Laden posed.

Bush and Blair have long given up hope of salvaging any political advantage from Iraq. The jigsaw is painstakingly being put together and Clarke provides valuable new pieces.

John Kampfner's book Blair's Wars is published by Simon and Schuster

Extract from

"From the interactions I did have with Bush, it was clear that the critique of him as a dumb, lazy rich kid was somewhat off the mark. When he focused, he asked the kinds of questions that revealed a results-orientated mind, but he looked for the simple solution, the bumper-sticker description of the problem. Once he had that, he could put energy behind a drive to achieve his goal. The problem was that many of the important issues, like terrorism, like Iraq, were laced with important subtlety and nuance. These issues need analysis, and Bush and his inner circle had no real interest in complicated analyses; on the issues that they cared about, they already knew the answers, it was received wisdom. Bush was informed by talking with a small set of senior advisers.

Early on we were told that 'the president is not a big reader' and goes to bed by 10pm . . . Others (Clinton, the first Bush, Carter, Ford) might have tried to understand the phenomenon of terrorism, what led 15 Saudis and four others to commit suicide to kill Americans. Others might have tried to build a world consensus to address the root causes, while using the moment to force what had been lethargic or doubting governments to arrest known terrorists and close front organisations . . . Such efforts may or may not have succeeded, but one thing we know they would not have done is inflame Islamic opinion and further radicalise Muslim youth into heightened hatred of America in the way that invading Iraq has done."