There is considerable legitimate concern that the commission that reviewed the incident engaged in a cover-up designed either to excuse a catastrophic failure on the part of the United States' national security apparatus, or even connivance of federal agencies in the attack itself.

And then there is the issue of possible foreign government involvement. The roles of the Saudi Arabian, Israeli and Pakistani governments and security services has never been adequately investigated in spite of the fact that all three countries had clear involvement with the mostly Saudi individuals who have been identified as the attackers.