Sudan's climate is traditionally described as an alternation of dry and rainy seasons. The political translation of this duality in Sudan's postcolonial history is the cyclical alternation of brief parliamentary rule and lengthy dictatorships ushered in by popular uprisings and military coups respectively. A series of other dualities are often employed to explain Sudan's turbulent history, civilian and military, Arab and African, Muslim and Christian, Muslim and pagan, center and periphery. Indeed, the promise of each new regime is that it will put an end to this “vicious cycle.”