Save yourself the wait for the various inquiries to report back. Read Kenneth Pollack's article from the Atlantic Review: Spies, lies and weapons: what went wrong. (It's very long...but an extract was published in the Guardian yesterday).
Explains how, and gives some guestimates why, Saddam pulled back from WMD development in the late 90s. And how the intelligence forces didn't get this.
Then goes on to the critical relationship between politicians and intelligence agents.
"The Administration gave greatest credence to accounts that presented the most lurid picture of Iraqi activities. In many cases intelligence analysts were distrustful of those sources, or knew unequivocally that they were wrong"
"Of course, no policymaker should accept intelligence estimates unquestioningly. While I was at the NSC, I regularly challenged analysts as to why they believed what they did. .. However, at a certain point curiosity and diligence become a form of pressure."
"To a great extent OSP [Office of Special Plans] personnel "cherry-picked" the intelligence they passed on, selecting reports that supported the Administration's pre-existing position and ignoring all the rest...[and] often chose to believe reports that trained intelligence officers considered unreliable or downright false."
"The Bush officials who created the OSP gave its reports directly to those in the highest levels of government, often passing raw, unverified intelligence straight to the Cabinet level as gospel."See, when it comes to intelligence, it's not what you've got: it's what you do with it that counts.