Abstract Background One critical challenge facing postconflict societies concerns the reintegration of former combatants as productive members of society. Public trust in the legitimacy of a peace agreement is a critical component of rebuilding the economic and social foundations of a war‐torn nation. Objectives We argue that the levels of trust of former combatants and confidence in their effective demobilization depend on two critical features of the postconflict environment: fears of insecurity and community engagement. Method We focus our analysis on Colombia and utilize data from the Latin American Public Opinion Project to create a multivariate time‐series analysis of public trust in two groups—leftist rebels and rightist paramilitaries. Results We find that both the fear of former combatants and the level of engagement individuals have in their communities help predict respondent attitudes about trust in former combatants and reintegration. Conclusion Fear and familiarity are key determinants in reintegration of former combatants.