Ummm ... Moussaoui was arrested on Aug 16, 1991 10 days After the memo.
Facts are a bitc&.
What you said would appear to reinforce my point - if someone knew about the contents of the memo and the M. arrest, the government would have pushed harder to get a search warrant of M's residence where, as you know, they eventually found all sorts of interesting stuff.
As I said, I doubt that they would have prevented the attacks, but they would have been a great deal closer.
D