6 ideas
The conflict is usually called 'the Southern Problem,' which casts the South as the anomaly to be managed. Khalid reverses this. The root problem is the northern ruling elite's insistence on defining the whole state as Arab and Islamic, so southern revolt is a symptom of how the center defines national identity, not its cause.
Northern regimes entered agreements with the South to gain relief from a military or political crisis, not out of commitment to the terms. When the pressure eased, the concessions were hollowed out or revoked. Unless the balance of power that forced a deal persists, the deal will not be honored.
On the eve of independence, southern members supported the independence declaration in return for a promise that their demand for federation would be given due consideration. Once independence was secured, the northern-dominated constitutional process dismissed federation. This founding broken pledge set the template for later southern distrust.
The 1972 Addis Ababa Agreement ended the first civil war by granting the South regional autonomy. Nimeiri later eroded it piece by piece: he interfered in southern regional government, moved over control of newly discovered oil, and in 1983 redivided the South and imposed the September Laws. The unilateral abrogation of the agreement's core guarantees reignited war under the SPLM/A.
Northern rulers used the imposition of Islamic law as a tool to consolidate power and outflank rivals, not simply as an expression of faith. By making sharia the law of a religiously plural state, they turned non-Muslims into second-class citizens. That made peaceful unity impossible without secular or confederal arrangements.
Because the North had repeatedly defaulted, the South would no longer accept autonomy granted from the center. It needed a structural guarantee: the right to secede by referendum, backed by international witnesses and its own army during the interim period. Unity had to be made attractive to the weaker party, or the exit option would be exercised.