In 1997, Charles Tripp remarked on the ‘peculiar’ resilience of Sudanese state structures, despite the crisis of the Sudanese state project and its fundamental imbalances between centre and periphery. His cautious prediction that the ‘deep frustration’ of ‘those who have historically been excluded’ would lead to the breakup of the territorial state has proven accurate. The leaders of the new Republic of South Sudan – and many of their international supporters and donors – have presented the successful revolt of this former marginal region as a fundamental departure from the history of the ‘Old Sudan’, establishing a tabula rasa for new state-building efforts. But the South Sudanese government nevertheless remains deeply aware of its historical heritage. As its own Vice-President warned in 2010, the new government has emerged out of the very centralising, authoritarian political culture against which the liberation struggle was fought.

The analyses of the structural inequalities in the Sudanese political economy on which Tripp was reflecting have been a vital corrective to simplistic assumptions of primordial racial or religious division as the cause of Sudan's conflicts. But the spatial centre-periphery paradigm may in turn simplify and obscure the local patterns of state formation on which this book has focused. More widely, scholars have increasingly challenged any assumption that the margins of states are peripheral to state formation, as Reid has recently argued: the violent ‘fault lines and frontier zones’ of northeast Africa have instead ‘defined the very nature of the states’.