When is military force an acceptable tool of foreign policy? Why do democracies use force against each other? David R. Mares argues that the key factors influencing political leaders in all types of polities are the costs to their constituencies of using force and whether the leader can survive their displeasure if the costs exceed what they are willing to pay. Violent Peace proposes a conceptual scheme for analyzing militarized conflict and supports this framework with evidence from the history of Latin America. His model has greater explanatory power when applied to this conflict-ridden region than a model emphasizing U.S. power, levels of democracy, or the balance of power.

Mares takes conflict as a given in international relations but does not believe that large-scale violence must inevitably result, arguing that it is the management of conflict, and not necessarily its resolution, that should be the focus of students, scholars, and practitioners of international relations. Mares argues that deterrence represents the key to conflict management by directly affecting the costs of using force. Conflicts escalate to violence when leaders ignore the requisites for credible and ongoing deterrence. Successful deterrence, he suggests, lies in a strategy that combines diplomatic and military incentives, allowing competition among heterogenous states to be managed in a way that minimizes conflict and maximizes cooperation.