Will terrorists kill innocent civilians in the years to come? Of course. They did so more than 100 years ago, when they were called anarchists—and a responsible nation-state must take reasonable measures to protect its citizens. But there is no way to completely eliminate terrorism.

The challenge that confronts us is how we will live with that threat. We have created an economy of fear, an industry of fear, a national psychology of fear. Al Qaeda could never have achieved that on its own. We have inflicted it on ourselves.

Over the coming years many more Americans will die in car crashes, of gunshot wounds inflicted by family members and by falling off ladders than from any attack by al Qaeda.

There is always the nightmare of terrorists acquiring and using a weapon of mass destruction. But nothing would give our terrorist enemies greater satisfaction than that we focus obsessively on that remote possibility, and restrict our lives and liberties accordingly.