Democracy, War Initiation, and Victory

How do nation-states' political institutions affect the relations between states? This article addresses that question by testing the predictions of different theories linking political institutions to war outcomes. Specifically, rent-seeking and regime legitimacy theories predict that all democratic belligerents are more likely to win wars because they fight more effectively. Alternatively, other theories focusing on the domestic political vulnerability of leaders and the marketplace of ideas predict that democracies are likely to be more careful about choosing when to start war. This would mean that only democratic initiators are more likely to win. Analyzing all interstate wars from 1816 to 1982 with a multivariate probit model, we find that democratic initiators are significantly more likely to win wars; democratic targets are also more likely to win, though the relationship is not as strong. We also find empirical support for several control variables, including strategy, terrain, and capability.