Conflict has been a feature of human society since time immemorial. Disputes that arise may be organized around social class, ethnicity, religion, region, or some combination of these factors. The struggle can be over economic opportunities, as well as political and civil rights, among other contestable factors. In peaceful societies, conflict is channelled into nonviolent means and institutions for both its expression and resolution. Civil war is not necessarily irrational, but a product of certain objectives, therefore amenable to rational-choice analysis. In low-income countries, civil war makes poverty reduction and growth difficult to achieve. Many contemporary civil wars have an ethnic dimension, as ethnicity is a strong uniting force. Grievances, therefore, play a major part in contemporary conflict, but greed - the desire to control resources and capture rents - also enters into the calculus of conflict. Ultimately, open warfare cannot emerge inside a society with a functioning social contract, as greed and grievances are managed and conflict is contained in countries with properly operating institutions. Consequently, conflict resolution requires the reconstitution of the social contract.