Why the hysteria?

CNN.com - Ex-White House aide defends 9/11 allegations - Mar 23, 2004
As my son pointed out, the Bush White House didn't have to respond with such hysteria over the Clark book. They could have just said that of course they were concerned about Iraq, its weapons, its destabilizing effect on the whole middle east, etc, etc. -- which has been exactly the justification for the whole war anyway. So why the hysteria?
I think I feel a conspiracy theory coming on here:
Take the Bush family ties to the Saudi royal family
+ the Saudi connection to Bin Ladens
+ Bush's derision for anything that Clinton or Gore thought was important, including the danger of Al Quaida
+ maybe, Bush being asked, quietly, either by his dad or by the Saudis, to back off Al Quaida and Osama because, after all, Clinton was really just wagging the dog, and Osama was on our side during the war with the Soviets, and the Taliban will let us put a pipeline through Afganistan if we act nicer to them.
So then, maybe, Bush did back off Al Quaida during his first months in office. Which turned out to be a horrible mistake. And maybe that why he wanted Iraq to be responsible for 9.11, not Bin Laden. And maybe that's why the Saudis had to be flown out of the country so quickly after 9.11, before they could say anything embarassing. And maybe that's why Bush became so terrified about Iraq and so fixated on the preemptive doctrine, because he didn't want to make that kind of mistake again. And maybe that's why he has been so reluctant about the 9.11 Commission. And maybe that why the reaction to Clark's book from the Bushies has been so hysterical.