The White House has criticised a former top security adviser who accused President George Bush of doing a "terrible job" in protecting the US from attack.
In response to claims of incompetence by Richard Clarke, White House spokesman Scott McClellan said the criticism was politically motivated.
With presidential elections on 2 November, McClellan dismissed all accusations as "deeply irresponsible" and "offensive", adding it was absurd to suggest that Bush could have prevented the 9/11 attacks.
Vice President Dick Cheney and Bush's national security adviser Condoleezza Rice also joined the campaign against Clarke.
Cheney said Clarke "wasn't in the loop" on decision making and suggested Clarke "may have a grudge to bear there since he probably wanted a more prominent position" than he had.
Book to embarrass?
The book at the centre of the row, Against All Enemies, was published on Monday.
It paints a picture of a Bush White House almost impervious to security concerns prior to 11 September and over-eager to pin the blame on Iraq after.
Clarke's attack is particularly sensitive for the White House as Bush has based much of his re-election campaign on his self-styled image as a "war president" who has taken on al-Qaida and made America "safer" with the invasion of Iraq.
Polls indicate the public has more trust in Bush than the Democratic candidate Senator John Kerry to handle security.
Clarke said Bush seemed obsessed with blaming Iraq for the attacks, and pressed him for information about alleged links between al-Qaida and the Iraqi government of Saddam Hussein immediately afterwards – even when it was clear there was no link.
The book makes clear Bush never asked him to make up evidence. However, he told CBS television one particular conversation left him "in absolutely no doubt that George Bush wanted me to come back with a report that said Iraq did this."
Kerry campaign claim
McClellan dismissed Clarke's book, and pointed out its author was best friends with Rand Beers – "who is the principal adviser to the Kerry campaign".
Clarke's former boss, national security adviser Rice, also rejected Clarke's claims.
"Richard Clarke had plenty of opportunities to tell us in the administration that he thought the war on terrorism was moving in the wrong direction and he chose not to," she said.
Clarke will give evidence this week to the official inquiry into the September 11 attacks, along with senior administration officials.