Remember the tears shed by Hollywood and the Left over Darfur and Sudan? A flood of tears for this foreign civil war. The propaganda was steady. Consistent with decolonization's history, the specifics of fighting, rape and killing were horrific. The film Hotel Rwanda was a guilt trip over Western inaction and hint hint, you can stop it from happening again in Sudan, America. No one really discusses Sudan anymore since the partition and Hollywood and the Left have moved on. South Sudan is an absolute failure.
South Sudan was created to end the civil war by separating the northern Islamic portion from the southern Christian portion of the nation. War and horror would end. South Sudan had 3/4 of the oil reserves of Sudan proper, so they could start out with some economic cushion. It did not happen. In a beautiful display of the thede concept, the South Sudanese went from united in their fight against the Muslims of the north to infighting between the Dinka majority and Nuer minority. For an example of the horror now being perpetrated on their former allies, soldiers who cannot be paid are allowed to rape women as payment. Africa!
The interesting thing in examining the split between the Dinka and Nuer is if one looks at modern scholarship, there is a focus on how the Nuer resisted the British more than the Dinka, therefore are magically punished for it today. If you read accounts of Cromer's time in Egypt, one can see how securing the upper Nile region was important to Cromer's administration of Egypt. This was not an undisturbed region with zero contact. There were Belgians and French in the area. That was the reason for the British to secure it because non-Brits might mess with the water and down the Nile, Egypt would be cooked. The Brits tried to administer that region, but the focus was on the Nile. The Dinka and Nuer did not take to organization and education as the northern Muslims did, and were of less importance and further reach from British administration in Egypt.
This is not a sad legacy of colonialism. This is tribal warfare returning now that the two groups cannot unite versus an outgroup. It is an interesting progression where Sudanese push the Euros out, then the Muslim, northern Sudanese fight the non-Muslim, southern Sudanese, and finally the Nuer fight the Dinka. This is nothing new and nothing to lay at the feet of the West. This conflict is a simple repetition of the countless tribal battles that Africa has had for ages. Similar to the problem of other post-colonial nations having internal squabbles, they have automatic weapons now. Cooperation between groups takes awareness that cooperation works as well as proof that cooperation and adherence to law and custom for various laws and rules works. It is not simply a matter of time. The switch must flip inside the group's mind that this will work.
It might never happen. Even if it does decades from now, Westerners will be asked to send money and forced take in refugees from this sad, war-torn area.