Alone, no. But, together we can. Flight 93 is the proof. It will never happen again, for the same reason they didn't succeed on Flight 93: the passengers realized what was going to happen and took action to stop it.
The tragedy on 9/11 occurred because of increasing government oppression and interference in airplane security -- who told airlines and passengers to just sit quietly, comply with hijackers, and let the feds negotiate.
I fly regularly for business and have had this same discussion over and over again with other frequent flyers and flight crew. If anyone tries to hijack a plane in the US, I'll be on top of them with my arm around their throat, even if I die trying. And, I know there will be plenty of other people on the plane that will be helping me.
You would think they would tail the guy after selling him the copier,maybe out his name on a watch list, but no, the Federal Bungling Idiots have screwed up another one.
HEADS SHOULD ROLL!!!!!!!!!
If the FBI was military, the people responsible would be OUT.
Instead, the people responsible will probably get a pay raise and a promotion.
Unless W puts his foot down and starts punishing the nincompoops that work for the Feds, security is just an illusion.