It’s the Roads, Stupid: Armed checkpoints along key trade routes—not natural resources—are the key to financing rebel groups and insurgencies around the world.

Control over people, territory, or natural resources is not the main pivot of civil wars. Groundbreaking new research reveals that, instead, it’s control over roads. From Afghanistan to the Democratic Republic of the Congo and from Syria to Somalia, armed groups are flocking to highways to finance their operations.

Across conflict zones, fighters are adopting a new, lean business model, which consists of setting up shop with a few Kalashnikov rifles on the roadside, taxing everything that moves. The problem is multinational companies and aid organizations are not exempt. The complexity of their supply chains effectively hides structural payments to rebels from view—adding to the success and sustainability of the roadblock business model.

In particular, western nongovernmental organizations operating on the ground are caught between rebels demanding transit taxes and the realization that if their activities, which structurally contribute to financing armed conflicts, were revealed, this would call into question the entire humanitarian project and wipe out much of their appeal to Western audiences. To prevent this and stop multinationals and aid groups from financing civil wars, the world needs new rules for global supply chains.