NATION-BUILDING, a cause derided by George W. Bush in his last presidential campaign, now rides on a large bandwagon. The Pentagon has proposed an initiative to train peacekeeping troops from Africa in preparation for future crises, and Mr. Bush is airing this idea at the Group of Eight summit this week in Sea Island, Ga. The State Department is planning a new office to coordinate post-conflict reconstruction, partly in response to a bill sponsored by Sens. Richard G. Lugar and Joseph R. Biden Jr. that would require such a unit. Yesterday a panel of foreign policy heavyweights convened by the Center for Global Development called for the creation of a Cabinet-level department to deal with post-conflict crises and with the challenge of heading off state failure. The idea that weak states can compromise security -- most obviously by providing havens for terrorists but also by incubating organized crime, spurring waves of migrants, and undermining global efforts to control environmental threats and disease -- is no longer much contested.

The question is whether the new resources that are likely to be spent on this challenge will be used effectively. The proposal to create a Cabinet-level department to coordinate the effort reflects a concern that without coordination resources may be wasted. At present, U.S. engagement with weak states is spread among various departments: the Pentagon trains peacekeepers, the Justice Department trains police officers, the Treasury sends out economic advisers, the U.S. Agency for International Development funds projects and the new Millennium Challenge Account backs successful developing countries. A new Cabinet department may not be the right solution, but there ought to be a new way to coordinate disparate development and post-conflict efforts.

Another debate will revolve around the balance between multilateral organizations such as the World Bank and the United Nations Development Program, which have considerable experience in post-conflict reconstruction as well as in development work, and the U.S. government's own efforts. There is a case for putting U.S. resources into U.S. agencies to cement America's global leadership. On the other hand, increasing contributions to multilateral bodies creates pressure on U.S. allies to do the same, so that U.S. money is leveraged. There is also some diplomatic benefit to the multilateral route. If the coming decade is to bring an increase in peacekeeping operations and interventions to prevent conflict, these are less likely to provoke resentment if they are organized under the flag of the United Nations or some other multilateral body.

There will be other debates too -- for instance, on the balance between preventive intervention in weak but not yet failed states and post-conflict reconstruction. A recent paper by Paul Collier of Oxford University suggests that preventive efforts spread across many potentially conflict-prone developing countries are likely to be less cost-effective than military interventions in countries that have already experienced wars and may suffer a relapse in the absence of help with their security. As the debate on failed states matures, the answers to these dilemmas may grow clearer. The good news is that the United States has begun to think seriously about a challenge that has sometimes not been acknowledged.