I first became a vegetarian when I was nine, in response to an argument made by a radical babysitter. My great change - which lasted a couple of weeks - was based on the very simple instinct that it's wrong to kill animals for food.
When I have clarified and exhausted a subject, then I turn away from it, in order to go into darkness again.
From a Christian point of view of course we do want a peaceful world, and I think September 11 did actually make people aware not only of vulnerability and how transitory life is, but there are forces of good and honor and justice which speak to us of God and his love for us.