Well, it turns out that WikiLeaks is having some ... unexpected results.
There is a mythology on the anti-war left that the Bush Administration made up a connection to Al-Qaeda in order to sell the war to the American public. The only problem is that the Bush Administration never said that: there was an active connection: Vice President Cheney came closest when he said that the two had cooperated.
As always, the reality is a tad stranger than one imagines. Sure, there was no inked treaty of cooperation between the two. But neither did the Bush Administration make something up. The idea that politicians in the Arab world may do one thing in public and another in private may be difficult to accept, but it is reality; further, there is nothing contradictory in the fact that Al Qaeda was sponsoring anti-Saddam forces in areas that Saddam no longer really controlled (Kurdish folk didn't like either) while at the same time discussing operative cooperation with Saddam.
Welcome to the world of Arab politics. Nothing is as it appears, your worst enemy becomes your long-time best friend, and everyone is fully able to hold multiple, contradictory viewpoints all at the same time because that is how the world works there: it's tactical thinking from those whose only interest is survival and advancement.
The anti-war left was and is extraordinarily naive when it comes to such politics and how they, the anti-war left, were deliberately misled, manipulated and in some cases killed when it served the purposes of their erstwhile friends in governments, local NGOs (got news for you: any NGO in Arab countries cannot exist without being a pawn of the government, sometimes more obviously so than others, but no NGO can exist in these countries without being compromised).
The American public believed, back then, that there was a connection. The Bush Administration did not dissuade them of this notion, for it was, as far as anything can be true in that corner of the planet, the case. It never existed as the prima causae belli in anyone's mind except for the rabid anti-Bush left.