The world wants America back. For the next several years, world politics will be reshaped by a strong yearning for American leadership. This trend will be as unexpected as it is inevitable: unexpected given the powerful anti-American sentiments sweeping the world, and inevitable given the vacuums that only the United States can fill and that others will increasingly demand that it fills.

This renewed international appetite for U.S. leadership will not merely result from the election of a new president in 2008, though having a new occupant in the White House will certainly help. But other, more compelling factors are fueling the world’s hunger for America. Almost a decade of U.S. disengagement and distraction have allowed international and regional problems to swell to the point where a growing number of foreign leaders are feeling that “someone had better do something, fast.” And very often, the only nation that has the will and means to “do something” is the United States.

Not that anti-Americanism will suddenly disappear; it never will. Nor will America’s enemies go away. But strong anti-American currents will increasingly coexist with equally strong international demands for the United States to play a larger role in world affairs. This trend, whereby American influence is welcomed and even sought, will become, in a manner not seen since 9/11, one of the defining features of the international political landscape.

Of course, the America that the world wants back is not the one that preemptively invades potential enemies, bullies allies, or disdains international law. The demand is for an America that rallies other nations prone to sitting on the fence while international crises are boiling out of control; for a superpower...