Peaceful Neighborhoods and Democratic Differences

Democracies are thought to behave differently from other states, particularly when cooperating in international institutions, such as alliances. We argue that these democratic differences depend on geopolitical environments that make cooperation possible. Although studies have demonstrated endogeneity between democracy and peace, few analyze the effects of this joint relationship on democratic differences. We explore this argument using the alliance literature and argue that the empirical finding that democracies are more reliable is driven by the tendency of democracies to cluster in peaceful environments. Alliances are more likely to be “scraps of paper” when found in more dangerous environments. By jointly modeling regime type and political environment using data on alliance termination from 1920 to 2001, we show that alliance reliability is a function of a threat environment. Our argument has important ramifications for a host of literatures focused on regime type, as well as current debates over the effectiveness of democratic deterrence.