No. Terrorism is, by definition, about using fear as a weapon to further your goals. Terrorism can be perfectly successful even if nobody dies -- it's all about playing your opponent's need to react against him. That's why even a fake bomb, or pre-announced bomb attacks IRA style are terrorism -- because there has to be a reaction to a bomb threat, at a relatively small cost a terrorist can force the opponent to do huge evacuations and bomb sweeps.
Completely ignoring the 9/11 would have been a better reaction that what the USA took -- but as usually with well planned terrorism, completely ignoring the attack would have been politically impossible.
> And what is a proper reaction to an organized attempt to kill civilians in your country?
A proportioned response against the attackers, instead of some of their various allies or complete third parties.
Also, what are people like me? And what is a proper reaction to an organized attempt to kill civilians in your country? I do not suggest that the US took the proper course of action, btw.