Well, that's the implication that everybody's taken from it, that they were just extraordinarily hypocritical, but I'm not so sure.
There was quite a bit of focus in the news on the alcohol and strip clubs and the like, because that's sensationalistic, but what I thought was the most telling was Ziad Jarrah living with his girlfriend in Germany. This wasn't something from the past, from before a conversion to fundamentalism; he telephoned her shortly before the hijackings.
I can certainly imagine these people engaging in vices that they believe to be utterly wrong, especially when under stress. People are led into temptation against their supposed best intentions quite frequently; they try, usually with some success, to keep such transgressions relatively secret, or at least isolated, limited, and erratic, separate from their normal lives.
But to live with one's girlfriend is to organize one's entire life in a way completely contrary to Islamic teachings. It is a declaration of non-adherence to fundamentalist beliefs, both publicly and privately.
So I conclude that Jarrah, at least, was not an Islamic religious fundamentalist. Since he was one of the operational leaders, that suggests that the others weren't either, or at least that Islamic fundamentalism wasn't the ideological foundation of the attack.
The most likely explanation is that the attack was organized by Iraq, not by al-Qaeda, although Saddam Hussein may have gotten some assistance from al-Qaeda in implementing it.
A second possibility is that al-Qaeda isn't really a fundamentalist group, that it's not based on strict adherence to Islam at all, in spite of bin Laden's public proclamations. (The trial of John Walker may be revealing in this regard.)
A final possibility is that the hijackers were working under stolen identities, and so, for example, the hijacker "Ziad Jarrah" is not the same person as the Ziad Jarrah with the girlfriend. The evidence would seem to be against this, however.
I find it difficult to believe that anyone would die for the sake of Saddam Hussein.
My experience of cult and religious fanatics is
that they generally are very mixed up people
who frequently live double lives.
I still am inclined to believe
that the 09-11 attack was the brainchild of Atta
who may have gone to Al-Qaeda and Iraq for financial and technical assistance.