The Impact of International Intervention on Conflict Trends
Civil wars are more frequent and longer than interstate wars. While these differences have held across the last 200 years, since World War II, they have become much more profound. We develop a formal model to explain how actions by the international community can prevent violent conflict. Our model focuses on the impact of international intervention — in particular, interventions that are much more powerful than the capabilities of the actors involved. When those interventions become more likely, actors see less advantage from fighting and so conflict does not happen. We argue that this level of intervention explains the decrease in the incidence of interstate wars, relative to civil wars, and also can explain when interstate wars do happen and when civil wars do not