A typical pattern of wealth redistribution seems to prevail, in some African countries, between rich and poor ethno-regional groups. A contract-theoretic model is presented for shedding some light on this phenomenon. The government promises a transfer to its potential opponent in return for not engaging in a civil war. The latter may break out because of the imperfect credibility of the government's commitment. This increases the cost of the required transfer of wealth, and may make it unfeasible. The model determines whether a military regime or a redistributive state prevails in a peaceful equilibrium. This depends on two parameters: (i) the relative fighting efficiency and (ii) the relative productivity of the two groups. The social cost of the different regimes is then compared, and their implications for aid policy are discussed.