From what I have seen it's more 1 then 2. In particular, remember that Cheney setup a seperate intelligence group in the DOD that channeled information to the White House without first putting it through the normal verification process.

This second group contained a lot of PNAC people, and in effect spent it's time looking for reasons to go to war, not carefully evaluating the evidence. This caused them to put way too much trust in Iraqi defectors, and other questionable evidence. These defectors often exaggerated what they knew, both because they wanted the US to attack Saddam and because doing so got them treated better in the US.

As for failure of the intelligence community world wide, it was just US and British intelligence that really got taken. And in both countries, the government took what intelligence provided and exaggerated it further to provide a reason to go to war. The intelligence groups of the other countries generally held the posistion that Saddam wasn't following the letter of the rules, but nor did it appear that he had any significant stocks of WMDs.

Jay