America's foreign policy suffers from what might be called the Superman dilemma. The comic-book-spawned Man of Steel incorporates a string of virtues and powers that are the envy of boys of all ages.

He is strong enough to defeat almost any enemy; fast enough to hie to any place in the world in time to stop fire, flood or avalanche; virtuous enough to avoid personal temptation; and wise enough to sort out the good from the evil. Moreover, with his telescopic X-ray vision, he can see evil deeds wherever they threaten the public order.

So how does he decide which crook to capture, which tidal wave to tame, which evil genius to put out of business or which little girl's kitten to rescue from a tree?

Fortunately for Superman's comic book and movie-screen creators, he doesn't have to. His writers send him off to this emergency or that -- sometimes a little old lady in trouble, sometimes a world -- based on how entertainingly they can have him use his superpowers to resolve the matter.

The shapers of American foreign policy should be so lucky. At the end of the century, as the University of Virginia's Philip Zelikow put it recently, America is stronger militarily, economically and politically than it has ever been before and stronger by far in all those areas than its nearest contemporary rival. It has the might to thwart "ethnic cleansing" in Kosovo; the influence to sway -- even save -- world markets; the reach to control the Persian Gulf; and the moral authority to return an exiled Haitian president to power.

And yet it is unclear that power -- even superpower -- is adequate to achieve the good things its wielders desire.

Slobodan Milosevic may not have gotten away with his attempt to rid Kosovo of ethnic Albanians, but are the region, the world and our own interests the better for our efforts to stop him? Saddam Hussein remains in office, no matter how fervently we wish him gone. Haiti, five years after the U.S. military restored Jean-Bertrand Aristide to office, is no nearer democracy, tranquillity or civil society.

But it isn't merely that much of what we've attempted hasn't worked very well. The more vexatious problem is that we don't know what to attempt.

Not long ago, as Zelikow, professor of history and director of the University of Virginia's Miller Center of Public Affairs, reminded a gathering of Ron Brown Scholars, the doing might have been tough, but the choosing was easy. There were two opposed superpowers. We went where anti-communist necessity took us, from Latin America to Vietnam to the Horn of Africa.

But anti-communism no longer serves as an organizing principle for our foreign policy, and we haven't figured out what ought to replace it, though it is clear that something must.

Imagine you are the strongest guy on your block, and you happen upon someone who's beating the stuffing out of a smaller neighbor. Or you're the richest person in town, and you come upon a starving mother and child. As Zelikow told the young scholars, it's possible to ignore violence or hunger that you don't see. But when it's in front of your eyes and you have the power to do something about it, isn't it immoral not to?

The reach of television is such that everything is at least potentially before our eyes: uprooted families in Serbia, bloody assaults on demonstrators in Tiananmen Square, genocidal savagery in Burundi, wanton killing in Liberia and Sierra Leone. And the reach of our power is that we can do something at least militarily in all of those places.

On what basis do we choose to act -- or not act?

Human rights? But almost every one of the wrongs that come on our screen involves a human rights violation.

Vital American interest? That huge tent could cover anything from threats to the world's oil supply to threats to General Motors or Chiquita bananas.

Zelikow offered a short checklist for guidance:

Do the governments in the affected region care about the problem as much as we do, and are they willing to back up that caring with real commitment?

Does the good we are likely to achieve outweigh the harm we're likely to do in the place where we intervene?

Does the good we do in that place outweigh the harm we may do to our nation's interests elsewhere around the world? Is the problem something we can help to fix (and not merely bomb)?

Not a bad checklist -- even for Superman.