Does institutional variation have implications for questions of conflict and peace? Theory indicates that it does, but extant studies that address this question treat such institutions as homogenous. Building on recent theoretical advances, I argue that cooperation on a wide array of economic issues and regular meetings of high-level officials provide member-states with valuable information regarding the interests and resolve of their counterparts. This, in turn, reduces uncertainty and improves the prospects of a peaceful resolution of interstate disputes. To test the effect of these two institutional features on the level of militarized interstate disputes (MIDs), I present an original data set that measures variation in institutional design and implementation across a large number of regional integration arrangements (RIAs) in the 1980s and 1990s. Employing multivariate regression techniques and the regional unit of analysis, I find that a wider scope of economic activity and regular meetings among high-level officials mitigate violent conflict. These results remain intact after controlling for alternative explanations and addressing concerns of endogeneity.