The aim of this crime is to eliminate--for all practical purposes--a black population that was becoming a thorn in the side of the government. The government's concern is that this population might become an effective political force, like that in the South, and ultimately demand a share of the oil revenues that fund the government, its leaders, and their economic allies.
Engineered social collapse is the method of genocide being used by the Sudanese government in Darfur. Engineered social collapse is well-understood, tried-and-true, having been used many times before in African nations including--in previous periods--by the Sudanese government itself.
Three steps are necessary to accomplish this crime--each of which is clearly displayed in Darfur:
1. Mobilize racial and ethnic hatred against the target victims, and promote violent, terrorizing attacks against the population to be eliminated. This mobilization can be accomplished in weeks, assuming there is an underlying mythology of hatred between groups, combined with political organizations who will make the genocide happen. In Sudan this has been accomplished through the military in combination with Arab militias. From the Guardian:
"The government was putting forward a programme of arming for all the people. I called our sons and told them to become armed.
"Our sons acquiesced and joined the Border Intelligence [a paramilitary force]. Some went into the Popular Defence Force [another militia]."
2. Destroy the ecological, social, and economic base of the target population. This requires a few months. In the genocide against the black population of Darfur, active destruction of livelihood started in earnest last winter. See the USAID satellite photos.
3. Allow starvation and disease to take its toll, usually over a period of many months. Genocidal leaders know that once the conditions of mass mortality are set in train, there is little that can be done to stop the main thrust of the genocide. See Eric Reeves' detailed analysis of the coming catastrophe, illustrated by a USAID timeline detailing estimated mortality over the next two years. Next October-December "Crude Mortality Rates" are projected to reach a level 20 times the emergency threshold (see exhibit above, or this pdf).
The special attractiveness of this method is that a genocidal government can initiate the collapse through a short, intensive campaign of terror lasting just a few months, and then sit back as the results unfold.
At the later stages a genocidal government can even ask the international community for "help"--knowing full well that adequate help--including military protection for victims--is unlikely to be offered and in any case can be rejected under one pretext or another.
For example, international humanitarian organizations can be allowed in, at least on a limited basis, because they are unable to stem the overall social collapse affecting the victims. A typical NGO, for example, may be able to help dispense water purification tablets and help people dig latrines in the camps, but it cannot supply the tons of food required to stave off starvation, nor can it contend with armed raiders who continue to terrorize the population.
The only effective remedy is one carried out on a massive scale, the "moral equivalent of war" to stop the raiding, stabilize the surviving people, and resettle and reestablish the victimized population in conditions where they can once again thrive on their own. This requires a combination of peacekeeping forces, large-scale feeding under the auspices of the World Food Program, and resettlement and reconciliation initiatives carried out over a period of years. The experience of Rwanda, by the way, shows that reconciliation can be accomplished, but only with profound attention by leadership and the community of survivors.