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 American empire will not disappear... because America does not have an empire.

The government can give citizens opportunity and it's their responsibility to take advantage of it.

American influence in the world is certainly considerable, but the United States does not control, directly or indirectly, the politics and economics of other societies, as empires have always done, save for a few special cases that turn out to be the exceptions that prove the rule.

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.

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.

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