Summary We suppose that civilians under threat prefer certain situations within a context of irregular war and endangered survival; they will prefer those situations associated with greater probabilities of survival. Using lexicographical preferences and belief systems, we have shown that civilians will choose not to remain in situations having a lower probability of survival. Linking into social networks allows for shorter deliberation processes, lower decision costs and faster convergence towards collective decision-making. Civilian displacement thus becomes the outcome of a rational decision-making procedure.