The attackers knew how to avoid detection by the National Security Agency and other technical intelligence outfits while organizing outside the United States. They also knew how to avoid suspicion once in the United States. That means they had a sophisticated understanding of how U.S. intelligence works and the discipline to avoid triggering suspicion. It is nearly unbelievable that an organization capable of carrying out such a complex operation would leave behind relatively obvious evidence.
There are also unconfirmed reports that pictures of Saudi dissident Osama bin Laden, widely viewed as a prime suspect in the attacks, and copies of the Quran were left in rental vehicles used by the suspects. For intelligence operatives who earlier exhibited remarkable skill, such theatrics do not make sense.
I thought that the car full of Arabic-language flight manuals seemed a bit too obvious.
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