Idk I think it would incredibly hard to organize something like this and expect nobody to ever find out, because people in on it will be guility for the rest of their lives and would probably want to come out with truth before they die... evenmore how many psycopaths do you need to find to organize it, people who wont be guility, or let's asume everyone involved were executed later... they would probably realize it and simply not do it in the first place because they realize that they either; live with quilt for the rest of their lives, be executed... etc
Also, imo way too much of a shock factor to plan, they could have just flew those planes into some empty ground or something and call it a terrorist attack regardless, because people on the plane died but the plane didn't get to its destination... but no let's plan planes fly into towers in middle of a big ass City.
I haven't checked any of the facts but what war it was, iraq or something... that was based on false "nuclear threat" accusations... later they just said that it was false intel. They didn't need to fake 9/11 to go to iraq war, i doubt they needed to fake 9/11 for whatever reasons you believe it was faked for.