We examine the role of FM radio in mitigating violent conflict. We collect original data on radio broadcasts encouraging defections during the Lord's Resistance Army (LRA) insurgency. This constitutes the first quantitative evaluation of an active counterinsurgency policy that encourages defections through radio messages. Exploiting random topography-driven variation in radio coverage along with panel variation at the grid-cell level, we identify the causal effect of messaging on violence. Broadcasting defection messages increases defections and reduces fatalities, violence against civilians, and clashes with security forces. Income shocks have opposing effects on both the conflict and the effectiveness of messaging.