Societies raise their grandest monuments to what their cultures value most highly. As the tallest buildings in a city noted for tall buildings, the Twin Towers of the World Trade Center were certainly monumental.

One thing worse than an America that is too strong, the world will learn, is an America that is too weak.

American power confers benefits on most inhabitants of the planet, even on many who dislike it and some who actively oppose it, because the United States plays a major, constructive, and historically unprecedented role in the world.

The attacks of September 11, 2001, were spectacular, riveting, grim, costly and searing. The shock that they caused reverberated throughout the world. What happened in New York and Washington and Pennsylvania ended the lives of thousands of people and changed the lives of many more. But they did not change the world.

People do not change when you tell them they should; they change when they tell themselves they must.

Certainly, protecting oppressed people, stopping ethnic conflict and promoting responsible governance are worthy goals. But none is as important for American security and prosperity as keeping the peace in the Middle East, Europe and East Asia.

All policy is a matter of gains and losses, upsides and downsides.