US National security adviser Ms Condoleezza Rice testified today "there was no silver bullet that could have prevented" the worst terror strike in the nation's history.
Condeleeza Rice
She said the nation "simply was not on a war footing" at the time of the attacks of September 11th, 2001.
"For more than 20 years, the terrorist threat gathered, and America's response across several administrations of both parties was insufficient," Ms Ms Rice told the commission delving into the attacks that killed more than 3,000, destroyed the twin World Trade Centre towers in New York and blasted a hole in the Pentagon.
In her widely anticipated testimony, Ms Rice offered no apology for the failure to prevent the attacks - as did former anti-terrorism adviser Mr Richard Clarke two weeks ago.
Instead, she said, "as an officer of government on duty that day, I will never forget the sorrow and the anger I felt."
Ms Rice's testimony in Washington, under oath and on live national television, came after weeks of White House resistance. President George Bush yielded in response to repeated public requests from members of the commission that an on-the-record rebuttal was needed in response to Mr Clarke's explosive charges.
Former White House aide Mr Clarke testified last month that the Bush administration gave a lower priority to combating terrorism than had former President Bill Clinton, and that the decision to invade Iraq undermined the war on terror.
In her prepared testimony, Ms Rice neither criticised Mr Clarke nor offered a point by point rebuttal of his appearance.
She said she made the unusual decision to retain him when the new administration came into office, saying, he was an "expert in his field, as well as an experienced crisis manager."
Ms Rice said confronting terrorists competed with other foreign policy concerns when the president came into office but added that the administration's top national security advisers completed work on the first major national security policy directive of the administration on September 4th. The subject, she said, was "not Russia, not missile defence, not Iraq, but the elimination of al-Qaeda."
She said Mr Bush "understood the threat, and he understood its importance. . . . He made clear to me that he did not want to respond to al-Qaeda one attack at a time. He told me he was 'tired of swatting flies'".
Ms Rice took the witness chair before an audience that included relatives of victims of the attacks, in which terrorists flew hijacked jetliners into the World Trade Centre and the Pentagon. In front of her sat the members of the commission. Behind her, in the front rows of the large hearing room sat relatives of some of the victims of the attacks.
Mr Bush was at his ranch in Crawford, Texas, and aides declined to say in advance whether he intended to watch the hearings.