Hatred is not conducive to clear-sighted analysis, which is why it is so often described as blind. In this respect The Bush Tragedy distinguishes itself from many treatments of the 43rd President of the United States. Jacob Weisberg is remorselessly critical. He does not hesitate to describe George W Bush's administration as an unmitigated failure with disastrous consequences for America and the world. But there is no hint of rage.

Weisberg achieves particular clarity by evaluating George Bush's presidency on its own terms. A deeply conservative candidate from an elitist Republican dynasty was never going to please cosmopolitan, liberal Democrats. But by empathising with Bush's ambitions and the emotional forces that created them, Weisberg's account is all the more devastating. He demolishes his subject with intellectual generosity.

Central to the analysis is a psychological conjecture about Bush's chief motive for entering politics: the contradictory urges to win approval from his father, the 41st President, and to escape from his shadow. Weisberg substantiates this thesis with forensic biographical research. Every choice that Dubya made can be explained by an obsession with the Bush family's collective mythology of entrepreneurship and moral purpose. George Jr was born without the intellect of a great leader and raised on the assumption that he should be one. The disparity between his aspirations and capabilities would have remained a private, personal trauma were he not afforded every nepotistic opportunity to elevate it into a national catastrophe.

This account also affords fresh insight into the roles of Karl Rove, Bush's campaign chief, and Dick Cheney, his Vice-President. Both men instinctively understood, serviced and manipulated their boss's childlike needs to suit their own political ends. Weisberg is right to class the whole drama a tragedy; history will surely judge Bush as America's most hubristic, flawed President. But it will take more than literary catharsis to undo the destruction he wrought on the world stage.