I personally believe that 9/11 was not planned bombing performed by Alkaida. Still after 12 years there are so many questions which have no answers. For example officials claimed pentagon building was struck by an airplane but on video reports there were no sign of what should have remained of that plane.
Actually we cannot prove that they were Arabic. Nevertheless, we cannot prove that they were not Alkaid, without credible sources. But as we all know theory of conspiracy had always been in U.S.A and always will be. There are other questions, on what reliable sources we can refer and assert that it was performed by mercenaries hider by C.I.A or they were Arabic?!
Ben laden family had close relations with Bush family. They had a common interest in oil business in Saudi Arabia. In fact BenLaden group is the world known contraction company operating in many countries across the globe. If they worked together once why they could not do it together for 9.11