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

The American political system is so porous, it's so open, it's so frustrating for those who are trying to make policy.

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.

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

After all, the past is our only real guide to the future, and historical analogies are instruments for distilling and organizing the past and converting it to a map by which we can navigate.

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.

The war on terror, I believe, will be waged by effective intelligence and police work and cruise missiles.