Now that the United States is having success in the war on terrorism in Afghanistan, it must consider how to handle the peace. Some urge a strong U.S. presence in postwar Afghanistan; others a much lower profile. Nation-building is at issue.

Wage war on terror, says Ted Carpenter. Forget about cleaning up afterwards. Director of foreign policy studies at Washington's Cato Institute, Mr. Carpenter thinks the United States is not capable of rebuilding Afghanistan, and it would be a mistake to try. "Fears of U.S. imperialism are endemic throughout the Islamic world and in many other portions of the world and we do not need to give those fears any degree of substance," he says. "An American leadership role in Afghanistan would I think re-ignite that paranoia about American imperialist ambitions in that part of the world, and that would truly be counter-productive."

Nation-building is a humanitarian dream, says Mr. Carpenter. Nations must build themselves. In the case of faction-ridden Afghanistan, that may not be possible. Ethnic rivalries prevent a sense of nation. A divided Afghanistan might do better.

Put bluntly, he says Afghanistan is not a matter of vital interest for America. "All America needs for its own security interests is that Afghanistan not become a haven for terrorists the way it did under the Taleban," he says. "And given what we have done to the Taleban for that offense, I think any successor regime in Afghanistan would be foolish indeed to venture down that same path."

That lesson may be lost on committed terrorists, says Gareth Evans, president of the International Crisis Group in Brussels and a former Australian foreign minister. If the only response to a terrorist haven is a military one, the United States may be kept very busy in a future Afghanistan. "Careening in with another military attack the next time the failed state fails again and becomes such a haven," he says. "But you have got to be prepared to address the security problem, to address the basic governance problem, to address the problem of providing economic opportunity and the problem of providing something in the nature of a viable system with a rule of law."

There is already impressive movement in this direction, says Mr. Evans. Afghans are forming a government that holds some promise.

It is a matter of humanity to rebuild a country after bombing it and uprooting its government, says Mr. Evans. But it is also in the U.S. interest to do so. "Dirty little wars in faraway places, collapsed states in faraway places do have the potential to impact upon us in the west and here in the United States far more directly and immediately than anyone used to think possible," he says.

Not only terrorism arises from such conditions, says Mr. Evans, but also massive refugee flows, illicit drugs and other crime, disease and environmental damage.

Nation-building, he says, is in everybody's interest. It does not always work. It may partially work. There are also successes, like Mozambique, where the United Nations intervened with U.S. help. "The electoral democratic environment is encouraging, producing a government that far from perfect, has been stable, a remarkable achievement after 16 years of civil war," he says. "What was one of the world's poorest countries has become one of Africa's fastest growing, and it is not now on anyone's list of places likely to harbor bin Laden."

What worked in Mozambique can work in Afghanistan, says Mr. Evans. So let's get to work.