In the words of one of the most respected leaders of the 9/11 Truth Movement:
"When the report of the Joint Congressional Inquiry into 9/11 was released in December 2002, it was met with considerable skepticism. That skepticism grew for a period of time but then was reduced to speculation about what was contained in the 28 pages that had been redacted by the Bush White House.
Various U.S. government leaders have since suggested that the missing 28 pages point to Saudi Arabia’s complicity in the 9/11 crimes. However such musings fail to discuss other important issues, like the links between the Saudi regime and the Western deep state, or the fact that, from the start, even the Saudis were calling for the 28 pages to be released. Discussion of the missing 28 pages also omits mention of the highly suspicious nature of the Inquiry’s investigation and its leaders." (Kevin Ryan, The 9/11 Joint Congressional Inquiry and the Missing 28 Pages, March 14, 2014)
A passing familiarity with the history and true nature of the relationship between "the Saudi regime and the Western deep state" is all that's needed to see the troubling ramifications of implicating the Saudis in the 9/11 black operation. As I said in a previous post, it amounts to implicating the West (via the CIA, the Mossad, ETC.) by default.
I haven't seen evidence that if the Saudis are involved, the U.S. is involved by default. That being said, I've seen a lot of evidence that strongly suggests that the U.S. was in fact involved. From what I've seen, I believe that certain U.S. officials were essentially coordinating all the major events of 9/11.