The U.S. is forming a partnership with Africa in which U.S. cash and technical expertise will back African troops in an attempt to stop the killings in Sudan. The effort was instigated by the African Union, and pulls together 3000 troops from Nigeria and Rwanda under one banner, with troops from more countries to be added soon.

The push by Africans to solve their own problems marks a significant shift, experts say. Rather than waiting for the outside world to resolve the crisis, “The AU has taken a very clear lead in saying, ‘These are African problems, and we will sort them out,’ ” says Mr. de Waal.

Success is far from sure, but any signs of cooperation between African people and the rest of the world is a hopeful thing.