An excerpt from a 2004 op-ed in the WSJ (free link):

We are now in a struggle with an extremism that expresses itself in the form of terror attacks, and in that we face what is probably the gravest threat to this country’s institutions, if not to its physical welfare, since the Civil War. When one tries to assess people who can find it in themselves to fly airplanes into buildings and murder 3,000 of us in a single morning, whatever else you can say about such people, they are very sure that they are right; and wouldn’t it be music to their ears to hear that our spirit says we’re not too sure that we are right?