I don't have any problem with it. I haven't seen any hard evidence of fact that Bush knew anything for him to issue a warning to the public on 9/11. Most of the hijackers themselves didn't know they were about to be sacrificed by kamikaze pilots according to what Bin laden as he admitted on the smuggled video tape. So how can you expect Bush or the intelligent agency to know.
There was a memo regarding an unprecedented number of ME's taking flight lessons here in America. There was a memo of a potential hijacking involving OBL. Bush was prompted to pass this info to other federal agencies...so he felt it at least that important enough. Yet he failed to warn the rest of us. Why? Especially when it is civilians who are typically the targets of muslim terrorists, and not federal agencies.
Terrorists won't dare challenge our military. They only target we unarmed and unaware citizens.