The President's man was calm under fire. But was he alert to the dangers?

As a former military commander, Colin Powell's trademark was remaining calm under fire. The stakes could not have been higher for him yesterday when, unflappable as ever, he appeared before a commission investigating the 11 September attacks.

It is hard to overestimate how much is riding on these hearings. Two and a half years after September 2001, the attacks in New York and Washington continue to gnaw at America's psyche and have become the overwhelming drive behind many, if not most, of the Bush administration's policies. But, as events over recent days have shown, they could also prove to be the Achilles' heel of President George Bush.

At issue during yesterday's hearings on Capitol Hill ­ and continuing today ­ is whether President Bush, and before him President Clinton, could have done more to counter the threat posed by al-Qa'ida and groups affiliated with the terror network. Even more pointedly, were the two administrations asleep on the job, blind to the danger of people who were prepared to do the unthinkable and strike at America's soft underbelly?

The answer, at least that provided by the White House policy co-ordinator on anti-terrorism, Richard Clarke, is exactly that. In a newly published book, Mr Clarke accuses Mr Bush of ignoring the threat from al-Qa'ida before 11 September and then seeking to hold Iraq responsible, despite being told by intelligence advisers that Saddam Hussein's regime had nothing to do with the attacks. "[Mr Bush] came back at me and said, 'Iraq! Saddam! Find out if there's a connection.' And in a very intimidating way ... I mean that we should come back with that answer," Mr Clarke said in a televised interview.

With everyone's eyes to the presidential election in November, there is potentially huge fallout if it is suggested that there was a failure of duty in regard to 11 September. Mr Bush has long campaigned on the claim that he is the man who is tough on terrorism and the only candidate who can guarantee America's security. His campaign team even tried to use fleeting images from the scene of the World Trade Centre in one of his television adverts, seeking to underline that claim ­ until they were forced to change the image after complaints from relatives of the victims.

For Mr Bush's likely Democratic challenger, John Kerry, the issue of 11 September has the potential to be a weapon with which to attack Mr Bush.

Should it be found ­ or more importantly, should there be a public perception ­ that Mr Bush was in some way at fault, it would be an extremely damaging blow. Mr Bush is already trying to fight off claims that the war in Iraq diverted attention and resources from the effort to take on al-Qa'ida.

It is against that backdrop that yesterday's public hearings took place. The inquiry, by an independent commission appointed by Mr Bush, is the latest investigation to try to uncover what failings, either by politicians or the intelligence-gathering community, may have been responsible for the worst terror attack on the US. The significance of the hearings is likely to be more in their political impact than because of any great revelations about 11 September. That is because there has been so much already revealed about the various shortcomings.

In December 2002, for instance, a joint investigation by the Senate Select Committee on Intelligence and the House Permanent Select Committee on Intelligence concluded that while there was significant intelligence available about the threat posed by radical militants, the intelligence community failed to "focus on that information and consider and appreciate its collective significance in terms of a potential terrorism attack".

It added: "Neither did the intelligence community demonstrate sufficient initiative in coming to grips with the new transnational threats." As a result, much of what took place yesterday was what might be called a collective case of backside-covering to guard against collective finger-pointing.

General Powell, one of many high-profile officials to give evidence, sought to rebut the allegations made by Mr Clarke that the administration had not done enough to make itself aware of the threat posed by al-Qa'ida. "President Bush and his entire national security team understood terrorism had to be among our highest priorities and it was," he declared.

Donald Rumsfeld, the Defence Secretary, said the 11 September attacks would have occurred, even if the US had killed Osama bin Laden in the weeks before. He said the plot was well under way when the Bush administration took office in January 2001. "Killing Bin Laden would not have removed al-Qa'ida's sanctuary in Afghanistan," he said. "The sleeper cells that flew the aircraft ... were already in the US months before the attacks."

General Powell's predecessor, Madeleine Albright, who served in President Clinton's administration, said: "President Clinton and his team did everything we could, everything we could think of, based on the knowledge we had, to protect our people and disrupt and defeat al-Qa'ida."

To some extent the independent commission, established at the end of 2002, has already made up its mind about the mistakes made by the Clinton and Bush administrations. Among its preliminary findings revealed yesterday, the commission has concluded:

* The Clinton administration had indications of links between Osama bin Laden and Khalid Sheikh Mohammed, said to have later planned the 11 September attacks, as early as 1995, but let years pass as it pursued criminal indictments and diplomatic solutions rather than military action.

* The US tried to get two successive Pakistani governments from the mid-1990s to denounce the Taliban by threatening to cut off support. But, "before 11 September, the US could not find a mix of incentives or pressure that would persuade Pakistan to reconsider its fundamental relationship".

* From 1999 until early 2001 the US sought, with little success, to persuade the United Arab Emirates, the only country to recognise the Taliban, to break off diplomatic ties.

Some of the diplomatic efforts undertaken by the Clinton administration appeared to have shown positive signs. The commission also revealed, for instance, that in a secret diplomatic mission Saudi Arabia won a commitment from the Taliban rulers in 1998 to expel Osama bin Laden from Afghanistan. The Taliban later reneged on the agreement.

The panel, formally the National Commission on Terrorist Attacks Upon the United States, concluded that Saudi Arabia was "a problematic ally in combating Islamic extremism".

Mr Clinton designated the CIA director, George Tenet, as his representative to work with the Saudis, who agreed to make an "all-out secret effort" to get the Taliban to expel Bin Laden.

The Saudi intelligence chief Prince Turki bin Faisal, using "a mixture of possible bribes and threats," received a commitment from the Taliban leader, Mullah Omar, that Bin Laden would be handed over. The Taliban's spiritual leader backed out of the deal during a meeting in September 1998 with the prince and Pakistan's intelligence chief. "When Turki angrily confronted him, Omar lost his temper and denounced the Saudi government. The Saudis and Pakistanis walked out," the commission's report said.

While many of the details being considered by the commission relate to Mr Clinton's administration, it is Mr Bush and his advisers who have been forced on to the back foot in regard to 11 September and the fight against al-Qa'ida.

The allegations contained in Mr Clarke's book, Against All Enemies, have been staunchly denied by senior members of the administration. The National Security adviser, Condoleezza Rice, wrote in The Washington Post this week that destruction of the terrorist network was its top priority. "This became the first major foreign-policy strategy document of the Bush administration ­ not Iraq, not the ABM treaty, but eliminating al-Qa'ida," she wrote.

There is a sense in Washington that these hearings, and the oxygen of publicity provided to them by Mr Clarke's allegations, could be perilous for Mr Bush and his team. Indeed, Mr Bush only agreed to establish the commission under intense pressure and he himself has declined to give public testimony ­ agreeing instead to sit with the panel's chairman and deputy at the White House.

DONALD RUMSFELD

The Defence Secretary said the 11 September attacks would have occurred even if Osama bin Laden had been killed before the terrorist strike. "The sleeper cells that flew the aircraft... were already in the United States months before the attack."

MADELEINE ALBRIGHT

The former secretary of state said: "President Clinton and his team did everything we could, everything we could think of, based on the knowledge we had, to protect our people and disrupt and defeat al-Qa'ida."

COLIN POWELL

Stridently defending the administration's stance on the threat from fundamentalists, the Secretary of State said: "President Bush and his entire national security team understood terrorism had to be among our highest priorities and it was."