Opportunistic rebel tactics in civil war: Evidence from Colombia

Abstract What explains the geography and timing of contestation in civil war? We propose a theory of opportunistic rebel tactics, in which insurgent commanders react to temporary shifts in the local balance of power to attack the state. We argue that these opportunistic strikes are enabled by two jointly necessary factors: (1) negative fluctuations in local repressive state capacity and (2) the expectation of civilian compliance with rebel incursions. We evaluate this argument on data from the Colombian civil war. Leveraging exogenous variation in local state capacity caused by landslide-induced road closures, we find that short-term negative shocks to repressive capacity increase the likelihood of insurgent-state clashes. However, this effect does not hold when local communities harbor strongly anti-insurgent attitudes, suggesting that state capacity and civilian behavior jointly shape rebel strategy and that popular opposition can substitute for state strength.