Carter's hopes died when the Soviet Union invaded Afghanistan and he ended up having to reverse policy and launch the military buildup that Reagan continued. Mr. Obama would be forced back into a war on terror if terrorist groups pull off enough damaging or frightening attacks to force this issue to the fore.

Unlike some, I don't claim to hold the mystic key to the future. But judging from past events, it seems to me that those who want to prophesy the imminent end of America's unique global role have a harder case to make than those who think we will limp on for a while, making a mess of things as usual.

The American people are extraordinarily comfortable, affluent, and secure. It's easy for us to make the argument that God's purpose is being fulfilled through history and through the rise of American power. And to some degree, it probably is.

Life isn't easy, and leadership is harder still.

When Edward Gibbon was writing about the fall of the Roman Empire in the late 18th century, he could argue that transportation hadn't changed since ancient times. An imperial messenger on the Roman roads could get from Rome to London even faster in A.D. 100 than in 1750. But by 1850, and even more obviously today, all of that has changed.

There is not a great sense that the Americans know what they are doing, or are making much progress in Iraq. And there is satisfaction in seeing that the Iraqis are successful in resisting the United States.

This very individualistic form of Protestant Christianity that became so basic in English and then American life is to a large degree responsible for the historical success of Britain and America.