Pre-print, Working paper: We study the determinants of international cooperation and its effect on trade. We rely on a unique database of 31,982 International Cooperation Agreements (ICAs) signed between 1945-2022 by 193 countries. Estimating bilateral gravity equations, we find that trade follows the flag: ICAs increase bilateral exports by around 1-3%, with stronger effects for South-South relations. We address potential endogeneity through panel approach and an instrumental variable that exploits the network structure of international relations. Further, using LPM we find that gravity forces explain country pairs entering an ICA. Importantly, we find that ICAs serve as stepping stones towards Regional Trade Agreements, confirming a previous step in Balassa (1961) theory of economic integration. Our results shed new light on the international relations-trade nexus and contribute to the current debate on friendshoring.