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The 911 conspiracy is most likely nonsense. It makes little sense because a muslim movement has been brewing since the early part of the 20th century and really started taking of during the revolution in Iran. It makes sense.
The conspiracy was started in part by irrational people and people that wanted to mask the real concerns behind the issue. The real concerns are about the cost of making things safe.
Firstly, there is no complete system for preventing the outside control of a plane. They could all have police on them, but that would be massively expensive. The cockpit doors could be made impenetrable but that would cost money. The plane could have knockout gas in the cabin, but that would cost money, and so on.
The state of the average building has been ignored. The fire safety in the towers was not well done. It was meant to handle a crash can fire. It is the case that planes fly through major cities everyday, and an accident could occur of the same variety. There is nothing to stop the same events from happening. It is my guess that there isn’t a building in America that could withstand a direct hit from a large aircraft. So, the conspiracy nonsense helps to divert attention that the country’s infrastructure is poorly designed and made from cheap materials.
Take note that you will find few news stories investigating how building and other things have been made more secure for the next attack. That’s because the wealthy do not want to spend the money to do you.
The sheep have been too distracted by a show to ask about how the rulers are going to take practical measures to ensure survival.
Thanks for the input, Mr. Predictable. You may be right, even though the official theory looks to have some pretty sizeable gaping holes. However my query was more on the geopolitical angle of things. 
What’s more geo than that?