Tribal allegiances will not be overcome by superficial and weak governments in sub-Saharan Africa. Only strong force wil keep the areas under control. Trying to set-up 'democratic' governments in areas with fundamental schisms is impossible without imposing strong military control. Western-style democracy is a utopian dream.
South Africa, often held up as a leader, is still fragile, with high poverty, disease and regionalism, development mostly under foreign control.
The desire culturally for like to live with like is hard to overcome.

Even in Europe, fractionalism is still strong- how many little self-governing entities in eastern Europe? Kosovo still a possible powderkeg for the next major conflict.

In western Europe, Belgium's Flemish and French are finding it almost impossible to live together and continue cooperative government. And there are predictions that the Scots will be self-governing in a couple of years. No genocide here, though, just a few brawls at the football matches.