The way wars are fought has changed starkly over the past sixty years. International military campaigns used to play out between armies at central fronts. Today’s conflicts find major powers facing rebel insurgencies deploying elusive methods, from improvised explosives to terrorist attacks. Presenting a transformative understanding of these contemporary confrontations, Small Wars, Big Data shows that a revolution in the study of conflict yields new insights into terrorism, civil wars, and foreign interventions. Modern warfare is not about struggles over territory but over people; civilians—and the information they might provide—can turn the tide at critical junctures. Drawing lessons from conflicts in locations around the world, Small Wars, Big Data provides groundbreaking perspectives for how small wars can be better strategized and favorably won.