This seems like an obvious one but I rarely see it: al Qaeda (etc.) and the American state (and later other states were invited in) are in cahoots. I don't mean like there's some kinds of secret ties between this dude and that dude or Osama is a CIA operative or it's all really false flags or whatever. I mean the more simple rational plan hit them and they figured it out as not an elaborate scheme but a totally obvious thing they should do. Is it because the story would be so boring?
The con: start an unending "war" from which both players benefit endlessly and tons of other people will be induced to participate willingly for financial or patriotic/religious reasons.
The members: it doesn't seem like it actually needs to be all that many, Osama (a billionaire with ties to another important state) is the obvious key figure, but I'm not sure he's essential he just already existed so they didn't have to create him.
The marks: everyone else.
The only objection I guess would be the part where the U.S. started killing the al Qaeda guys*. But I feel like simple betrayal by one of the con men explains this, not to mention the fact that once there's enough marks in the con they can't be controlled and would be willingly killing each other, that's a key part of the whole con. Why does nobody remark on how al Qaeda has never seemed to seriously target high level Western officials anywhere?
The timing is also essential, you can't do the con as long as there's other rival states, like before the Soviets would have started snooping around, before them the U.K., etc. The U.S. becomes the lone superpower and goes looking for threats and lands on "stateless terrorism" which is exactly the perfect setup for this con!
I'm sure
somebody has gone into this further, but I never see it from the "normies" of conspiracy people, when you see the similar version it's just something done by the American state for their own goals, all of the benefits accrued to al Qaeda and related are ignored. Is it because conspiracy theorists only seem to be prone to believing completely absurd things that fall apart without fantastical leaps of logic and near supernatural abilities where everyone's motives and decision making is completely irrational?
*
"Hey, Barry, it's O, I'm dying man, time to come find me."