Whilst a perfunctory read of the various 'sources' give a prima facia case of conspiracy, linking numerous disparate threads into a coherent case requires a great deal more.
The veracity of source, intent to mislead, un-connected events linked by hindsight and lack of real detailed knowledge in the public domain about the Al Qa'ida group means that the analysis is so suspect as to be almost ridiculous. Two simple examples:
'Pre-positioning of UK troops in Oman by mid July.'
Saif Sareea had been planned for 2 years (believe it or not!) and the full exercise strength was not achieved until late September.
'17000 US and 23000 NATO troops pre-positioned in Egypt for Ex Bright Star in July.'
Again, Bright Star is an annual exercise, there'll be another one next year.
Trying to tie together non-related facts to make a conspiracy theory needs more than the occasional reporter saying that the CIA knew. On that basis the aliens have been here and are amongst us now, and Adolf Hitler is alive and well and living in Skegness.
Try this for a theory:
Osama Bin Laden, a religious zealot, was hired and then let down by the CIA during the Russian occupation of Afghanistan. He became increasingly angry towards his former employers when they protected the Kingdom that had thrown him (Saudi Arabia) out by removing Iraq from Kuwait. His religious bigotry then viewed the 'infidels' continued presence in the land of the two Holy Mosques with increasing rage. Following a number of attacks, each increasing in intensity, he realises that the US (and the West in general) cannot/will not really retaliate to any great effect and decides to attack the US mainland in a 'spectacular' manner. At his instigation, his followers crash 4 passenger aircraft into the WTC, Pentagon and open farmland causing the deaths of more than 5000 people. The US and the West decide to act and attacked the vipers nest where it resided.
Conspiracy? Yes, I'd say that was quite a trail to follow. Stop reproducing such gibberish and use your own mind to think why the US/UK/EU/NATO/Russia/ASEAN/ALL Muslim countries (Iran included) have backed this campaign - and no, it is not oil.