Stark warning at the Darfur talks: Serious danger of major regional war unfolding - Alex de Waal
Mr de Waal said the situation on the ground in Darfur was deteriorating and becoming more complicated.
In public, some of the rebels are holding out for a regional Darfur government.
But the BBC's World Affairs correspondent Mark Doyle says Khartoum sees this as the thin end of a dangerous trend and is resisting.
In the southern peace deal, SPLM rebels gained control of some ministries in Khartoum and a share of Sudan's oil wealth.