Over the past decade, we have seen a resurgence of civil conflicts in Africa, the Middle East, and southeast Asia, as weak states are increasingly threatened by non-state actors, such as organized crime groups, terrorist organizations, and insurgents. These wars endanger millions of people—including some of the world’s most at-risk populations—by exposing them not only to violence, but also displacement, environmental degradation, and economic destruction. To effectively protect them, leaders and policymakers need to be able to predict exactly where, when, and how insurgent violence will break out and spread.