Democratic Victory and War Duration: Why Are Democracies Less Likely to Win Long Wars?

Using costly-process models of war with democratic citizens and soldiers, this article explores two contrasting claims on the negative association between the probability of democratic victory and the duration of war. As a claim holds, democracies are not militarily disadvantageous in long wars. Rather, they need long time to produce a surrender decision, because they incur audience costs if they break a prewar commitment too hastily. According to the other, democracies are less likely to win long wars, because their battlefield effectiveness declines over time. Although the underlying logic differs between the two claims, they offer analogous predictions as to military strategies consistent with empirical findings that while democracies could raise their chances of victory with a shortening strategy (e.g., maneuver), autocracies might have mixed incentives for shortening and protracting strategies (e.g., attrition). These results imply that both the mechanisms might be at work in a democracy's prosecution of war.