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

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

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.

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

In the past when a country became as powerful as the United States, other countries would band together to clip its wings. But that isn't happening now and I don't think it's not going to happen, because other countries are not threatened by us, and they secretly appreciate the services that we provide, even if they don't usually say so.