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

The government in Khartoum, dominated by Arab Muslims from the north of the country, has offered a measure of autonomy to southern Sudan, whose inhabitants are mainly black African Christians or sky-worshippers.

ECONOMIST: A glimmer of hope

And the northern government based in Khartoum under President al-Bashir was supposed to take several steps, including confirming a border between the north and the south, taking political steps or steps towards political reform, and third, working out agreements around the issue of oil, because oil have been discovered in the southern Sudan, which is what this dispute is really largely about.

NPR: Africa Update: Somalia, Eritrea and Sudan