There is an emerging consensus that international intervention can secure peace by helping combatants resolve commitment problems following civil wars. But how do interveners accomplish this? Some suggest that intervention primarily works through military coercion, while others propose non-military instruments. We build on the existing literature to theorize that interveners commonly condition political, economic, and legal incentives on compliance with peace processes. Despite a rich literature on intervention, scholars have only started to test the underlying instruments. This article takes a critical step toward this end, examining peacekeeping missions led by the United Nations from 1989 to 2012. Contrary to conventional wisdom, we show military coercion is neither commonly used nor necessary to ensure peace. Missions that employ conditional incentives—on which we collect original data—are consistently correlated with a reduced risk of conflict recurrence, even when controlling for observed selection effects, and regardless of whether they are also authorized to use military coercion.