Jeffrey Herbst, States and Power in Africa (2000).

Quick Summary: Due to low population density, lack of interstate conflict, and the perverse role of colonialism and the international state system, African states did not develop institutions that could effectively control and police their territories.
Summary: Herbst is putting forth a new theory of state formation in Africa. He starts with the assumption that Africa is characterized by state failure, and that this can be traced back to the fact that Tilly’s pattern of state development did not occur in Africa. Why not? Herbst chalks it up to different structural factors: Africa did not suffer from a scarcity of land, rather they suffered from a scarcity of labor.  This explains why states did not fight over land, but fought over people. There was no need or incentive to defend a well-defined territory, so bureaucracies and institutions to do so did not emerge. So we get a situation of low population density and an absence of external threats, so elites relied on plunder and resource exploitation to acquire wealth/resources rather than the European route of institution and state building. During the cold war, African states could rely on external assistance to meet military power and resource needs.  This continues today due to foreign aid policies.
Important Insight: Structural conditions differed from Europe, so the state never had to fight for resources or ever employ military power in the way that was conducive to state formation on Tilly’s account.  This explains Africa’s weak institutions.