Following several decades during which violent civil conflict was common in African countries, the period from 1990 onwards was notably marked by a spreading and deepening of adherence to democratic principles. However, it is true to say that many African countries are still experiencing political instability and civil unrest. This raises the question of why these countries cannot attain sustainable conflict resolution. Drawing on economic ideas about contracts and institutions, this paper outlines a conceptual framework for thinking about the role of constitutional rules in achieving political stability, and we elucidate the main requirement for sustainable democratic systems. The gist of the argument is that constitutional rules must become self-enforcing in order to safeguard democratic systems and to avoid relapses into violent civil conflict. We discuss selective examples where constitutions do not adhere to the framework of self-enforcement, making them unable to prevent the recurrence of civil war in these countries.