Two phenomena have been recently utilised to explain conflict onset among rational choice analysts: greed and grievance. The former reflects elite competition over valuable natural resource rents. The latter argues that relative deprivation and the grievance it produces fuels conflict. Neither the presence of greed or grievance is sufficient for the outbreak of violent conflict, something which requires institutional breakdown, which we describe as the failure of the social contract. The degradation of the social contract is more likely in the context of poverty and growth failure. We provide a synthesis of the greed and grievance hypotheses. Copyright © 2008 John Wiley & Sons, Ltd.