So we are at war. The United States leads a loose international coalition pledged to destroy the worldwide terrorist networks, which produced the 19 young men who on September 11 randomly killed thousands of civilians and destroyed billions of dollars worth of flagship property.

America's war aim is not just retributive justice (though it certainly is that, as far as the terrorists are concerned). It is primarily to prevent such attacks in the future by eliminating their source. War is always evil, but in our nightmare scenario, where more terrorism as a follow-up is confidently promised, a war of suppression appears to most as the lesser evil. However burdensome, it is surely the best and only rational course.

We need to be clear that terrorism, whether religiously, politically, or ideologically motivated, begins as a mindset—what the Bible calls a thought of the heart. In this case, alienated persons are driven by bitterness at real or fancied wrongs, by some form of racial or class hatred, and by utopian dreams of better things after the present order has been smashed. This is an explosive mix.

Terrorists think of themselves as both victims and avenging angels. They act out their self-justifying heartsickness in a way that matches Cain killing Abel. They see themselves as clever heroes, outsmarting their inferiors by concealing their real purpose and by overthrowing things they say are contemptible. So their morale is high, and conscience does not trouble them. Gleeful triumphalism drives terrorists on; they are sure they cannot lose. This is what the anti-terrorism coalition is up against. It is only realistic to anticipate that ridding the world of terrorism will be a long job.

Terrorism is something countries like Ireland ...