My personal hunch is
that ATTA was the mastermind
and organizer
of the whole September 11th business,
and that bearded fool in Afghanistan
knew nothing about it.
(Why would ATTA take the risk
of having someone spill the beans????)
Initially formulated his plans
with his friends in Germany.
Eventually they found others
to go along with them.
It probably was ATTA
who approached the Iraqis
and asked for an anthrax sample.
Saddam, who may be dying of cancer, said
"What the heck! Why not give it a try!"
(Not the first time Saddam was known to be reckless.)
If my hunch is correct,
ATTA wanted the world to know.
I doubt anonymous martyrdom was a sufficient force to drive him.
He wanted glory
in this world as well.
I do however believe Osama knew about it, at least generally enough to fund it and supply the extra martyrs - and, according to him, to speculate that the floors above would crumble.
I've posted this as speculation for some time. Bush's recent "axis of evil" speech suggests that the U.S. government now has evidence confirming the existence of such an alliance.