Military interventions often involve cooperation between different national armies. In this project, we investigate the extent to which the porous international borders in the Sahel region affect geographical patterns of conflict, and how the creation of an international armed force that can cross borders (the G5 Sahel) changed these patterns. We find that the G5 mission lowered the intensity of conflict locally, and that it changed patterns of geographical conflict propagation. (Co-author: Marion Richard (UCLouvain/PSE))