Several possible explanations have been given for why democracies maintain peaceful relations among themselves. This article examines the role of domestic political institutions in establishing market relations and the degree of interference in domestic economic relations. It is argued that less representative regimes are more likely to establish pervasive policies delivering rents than more representative regimes. Pervasive rents, in turn, alter the relationship of domestic and international prices, which affects how countries choose to participate in the international economy, Republics, where rent-seeking may be pervasive, but rents tend not to be distorting, fit into liberal international systems with greater ease than other types of regimes; republics, therefore, find it more attractive to meet their international needs through trade than do nonrepublican regimes. By exploring the importance of regime type for the formation of international preferences, questions about relations between democratic states are linked to broader issues of grand strategy and policies to foster international peace and stability.