Are you saying that killing 2-10 thousand people is NOT an act of war? That is complete bullshit.
The insanity required to commit these acts is the problem. It isn't about religion (though I blame the doctrine of conversion for starting the whole thing 1000 years ago). It isn't about politics. It is about the insanity of a small number of influential zealots, not different than the bastard(s) that bombed Oklahoma City.
They need to be stopped at any cost. The acts of 9/11/2001 are outside the bounds of civilized discourse, answerable only by war. They are heinous and threatening enough to justify retaliation outside the bounds of due process. That is war.
Fanaticism of any kind (at home or abroad) is the enemy of civilization. Do not tolerate it in others or yourself. This is as true in Ireland, Israel, and Afghanistan as it is in New York.