At the same time, a variety of other mediators, including the Qataris and a new American special envoy to Sudan, Scott Gration, have been encouraging the disparate rebel groups to resolve their differences and form a more coherent negotiating body.

ECONOMIST: The crisis in Darfur

Scott Gration, Barack Obama's energetic new special envoy to Sudan, believes that the best chance of peace for this divided country remains the Comprehensive Peace Agreement (CPA) signed in 2005 between the Islamist government in Khartoum, in the north of the country, and the former rebels of south Sudan, who are quite separate from the Darfuris, and had been fighting their northern masters for most of the past half-century.

ECONOMIST: Sudan and Darfur