Why would the CIA be so wrong? Wasn't there any way to proove their point? Apparerently, no agent was available on the spot. Info came only from Iraqis who fled the country sometimes a generation ago. Is it sensible to believe them without checking?

No the US, including the President and Vice president of 2 administrations, Britain, Russia and Germany all failed to have better, cross checked sources.

Clinton, when he left the office, told Bush what were the most dangerous issues; he cited by decreasing order of importance: Bin Laden, the Israel-Palestine conflict, the India-Pakistan conflict, North Korea and then Iraq.
Bush didn't wait to solve the Bin Laden issue before dealing with Iraq.
But the roadmap to peace first must go through Jerusalem before Baghdad.

That was Clinton's after the fact stated current opinion. Somewhat revisionist in that the public record is full of Clinton and Gore statements about the danger from Iraq but very little in Bin Laden. Curious. Of course, his limp efforts to capture OBL as he agonized over the legality of arresting OBL is public record. I watched his interview on CNN where 15 minutes after castigating Bush for being 'unilateral' on Iraq, Clinton reversed field and said he would have done whatever it took to capture OBL completely irrespective of international opinion or consequences. How hipocritical, revisionist and self-serving is that? Star-struck interviewer Christine A 'swallowed' it wholesale. He's a masterful BS artist.

-p (CNN: Clinton News Network)