Ensuring Peace: Foreign-Imposed Regime Change and Postwar Peace Duration, 1914–2001

This research note develops a new explanation of postwar peace duration: periods of peace following wars last longer when the war ends in foreign-imposed regime change. This study tests this hypothesis on a new data set (an expansion of Fortna's (2004) data) of all periods of peace following interstate war cease-fires, over the period 1914–2001. It also tests for other possible factors affecting postwar peace duration, including international institutions, the revelation of information during war, third-party intervention during war, postwar changes in the balance of power, regime type, past conflict history, and others. The article finds strong support for the central hypothesis that peace lasts longer following wars that end in foreign-imposed regime change. This pacifying effect diminishes over time when a puppet is imposed, but not when a democracy is imposed. There are other results, including that the strength of a cease-fire agreement has almost no impact on peace duration.