A sound truck drives slowly through a neighborhood in a small city in west-central Colombia. A soldier aboard plays a recorded audio message, jacked in from his phone, encouraging members of armed groups to turn themselves in and demobilize.

This seems like an empty exercise. These messages, broadcast by radio, may sometimes work on homesick guerrilla recruits in remote jungle encampments, convincing them to disarm. But in the middle of a population center like Chaparral, Tolima, any armed-group members are likely to be un-uniformed and mixed in with the population. The promise of returning to one’s home and family, who are probably right there in town, doesn’t make particular sense.