The following quote is from Jay Rosen’s "Rollback" piece at Press Think:

A PressThink reader pointed me to this testimony
at a public hearing organized by Senate Democrats on the Valerie Plame
disclosures and the effect of outing an agent (Oct. 24, 2003). (Also
discussed by Talk Left.)  The speaker is Vince Cannistraro, former Chief of Operations and Analysis, CIA Counterterrorism
Center, and now a terrorism consultant. His is one of the better
descriptions I have found of that strange feature of the Bush governing
style Suskind called “a retreat from empiricism.”

CANNISTRARO: …There was a pattern
of pressure placed on the analysts to provide supporting data for
objectives which were already articulated. It’s the inverse of the
intelligence ethic. Intelligence is supposed to describe the world as
it is and as best you can find it, and then policymakers are supposed
to use that to formulate their own policies. In this case, we had
policies that were already adopted and people were looking for the
selective pieces of intelligence that would support those policy
objectives.

This describes exactly why the Downing Street memo story was so important. Bush and his honchos let it be known that they were going to war, wanted Blair and his cadre to come along for the ride, and they knew they needed "justification" to sell the whole idea to the "people."

It also ties in with something that Steven Leavitt, one of the authors of Freakonomics, says: (I’m paraphrasing) that morality is how we’d like the world to work, whereas economics can represent how it actually does work.

I know many liberals who would argue that Bush and company are anything but moral, but I tend to believe that the President truly believes in the Kool-Aid he’s trying to peddle to the rest of us (not so sure about his honchos).  What makes it scary is that because this is a moral issue for him (freedom, good vs. evil, etc.) he cannot acknowledge that he may have been, or continues to be wrong in any way.