THIS week's televised hearings of the National Commission on Terrorist Attacks Upon The United States have made riveting viewing. With witnesses including Colin Powell, Donald Rumsfeld, Director of the CIA George Tenet, as well as senior office-holders in the Clinton administration such as Madeleine Albright and Sandy Berger, we were watching and hearing people who have been close to the seat of American power over the past fifteen years. There was little doubt, however, that the star witness turned out to be a man of whom few people had heard - Richard Clarke, a senior civil servant who was principal counter-terrorism advisor to President Clinton and, until his retirement about a year ago, to President Bush also. Last weekend Mr Clarke published a book in which he alleged that after taking office in January 2001 the Bush administration downgraded the importance of counter-terrorism work and instead concentrated on the problem of Saddam Hussein and Iraq. For obvious electoral and other reasons this allegation was immediately denied by the White House which for several days has been smearing Mr Clarke's name in every conceivable way. The degree of concern over his charge can be judged by the appearance in the London Independent newspaper yesterday of an article by the US Ambassador to the United Kingdom, William S Farish, which repeated the criticism of Mr Clarke's facts and character already heard in the United States and, specifically, said that his book was “a political attack on President Bush and his administration in the hothouse atmosphere of a presidential campaign season”. In impressive testimony to the Commission Richard Clarke gave a point-by-point account of how his attempts from January 2001 to get high-level and urgent attention for action against al-Qaeda were blocked or ignored by the President's National Security Advisor Condoleezza Rice, to whom he reported. It was not until early September 2001 that a full discussion of his proposals took place; although most of the recommendations were accepted for further consideration, they were made obsolete by the events of September 11 which he had foreseen in a letter to Ms Rice dated 4 September in which he suggested that she should ask policymakers “to imagine a day after a terrorist attack, with hundreds of Americans dead at home or abroad, and ask themselves what they could have done.” Condoleezza Rice has publicly challenged the accuracy of Mr Clarke's account and insisted that the Bush admininstration gave full attention to the threat from terrorism and by September 2001 had developed a comprehensive strategy to deal with it. However, although she has been willing to write for the newspapers and appear on TV, Ms Rice has refused to appear before the National Commission to give her own account of the events covered by Mr Clarke. This refusal, she said, was based on legal advice she had received about the “separation of powers” under the US Constitution; it is possible, though, that a surprising public disagreement with the Vice-President Dick Cheney may have had rather more to do with her refusal. In a radio interview Mr Cheney described Richard Clarke as having been “out of the loop” but Ms Rice denied this to reporters, saying that he had been “at every meeting held on terrorism”. Richard Clarke did not emerge unscathed from his appearance in front of the National Commission; he was criticised for apparent discrepancies between his book and his evidence to the Commission, but the truth of his central accusation that the Bush administration was more concerned about Iraq than about al-Qaeda - was not seriously challenged, even by the Republican members of the Commission. When the Commission's report is published in July it is likely to have a major impact on the presidential campaign.