Bob Woodward bases his allegations on interviews with senior administration officials. One of his key charges is that insurgents are attacking U.S. forces in Iraq as many as 900 times a week.
White House counselor Dan Bartlett says the administration is adapting to increased violence.
"The enemy has been very good. They have been, to an extent, more vicious and more violent that we probably originally expected."
Woodward writes that on July 10, 2001, two months before the 9/11 attacks, Central Intelligence Agency director George Tenet called a special high-level meeting based on indications of an imminent al-Qaida strike in the United States.
Former White House Terrorism Advisor Richard Clarke says he was there.
"The message from the Director of Central Intelligence and from me was that there was still going to be a major al-Qaida attack in the next several weeks."
Bob Woodward alleges that Condoleezza Rice, who was National Security advisor at the time, seemed to brush off the warning. Secretary Rice says she does not recall any such meeting and none was reported to the bipartisan 9/11 Commission, which investigated the terrorist attacks.
White House spokesman Tony Snow says there was a meeting, but that Woodward reports it out of context.
People are taking a look at all of the documents to find out what was reported and what was not to the 9/11 Commission. As a matter of fact, there's a trip to the Archives right now to try and sort through all of that.
Members of the opposition Democratic Party have used the Woodward book to accuse the White House of misrepresenting the war in Iraq.
Pennsylvania Congressman John Murtha said "I spoke out two years ago and said we can't win it militarily. The military leaders have told me that. General Pace [the Chairman of the Joint Chiefs of Staff] has said this publicly, and they continue to put our troops in harm's way."
Woodward says the head of the U.S. Central Command, General John Abizaid, met with Congressman Murtha last year and indicated that both men were nearly in agreement on the need for a U.S. pullout from Iraq.
White House Spokesman Tony Snow says President Bush demands honest answers about Iraq.
"As a commander in chief, it is not your job to live in a state of delusion. You know in a time of war you got to get it right. You have to do your very best at all times. That means push the generals about the facts on the ground."
Woodward and fellow Washington Post reporter Carl Bernstein helped expose the Watergate scandal, which forced President Nixon to resign in 1974. State of Denial is Woodward's third book on the Bush Administration. The first two were well received by the White House.