American foreign policy, for all its shortcomings, has underpinned political stability around the world.

The real threat to world stability is not too much American power. It is too little American power.

The windfall of great riches can, if mismanaged, make things worse, not better, for the recipients.

The United States contributes to peace in both by serving as a buffer between and among regional powers that, while not preparing for armed conflict, do not fully trust one another.

While analogies are useful, however, they can also be misleading. They smuggle in assumptions that can be wrong.

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 main division in the world is between democratic and undemocratic countries.