We study the role of FM radio messaging in discouraging violent conflict by armed groups. Focusing on the Lord’s Resistance Army (LRA), we collected unique information about defection messaging by radio stations in the four countries where the LRA has operated (DR Congo, Central African Republic, South Sudan and Uganda). We exploit time and geographical variation, along with random topography-driven variation in radio coverage, to capture the causal effect of the intensity of messaging on violence, and on the LRA’s strategic behavior. Higher intensity of defection messages leads to a decrease in violence, measured in both number of events and fatalities. We show that this outcome is mainly explained by an increase in defections among LRA members. In areas with higher intensity of messaging, we observe a strategic shift as the LRA tries to compensate these membership losses by “recruiting” new members through increased abductions, and engaging in higher levels of looting to reward new and existing members.