Do UN peace operations lead to more terrorism? Repertoires of rebel violence and third-party interventions

Recent research suggests that UN peacekeeping operations (PKOs) reduce conventional violence. However, rebel groups have been increasingly using a combination of conventional and non-conventional violence, for example, terrorism. Little is known about whether and under which conditions PKOs shape rebels' incentives to resort to more terrorism. At the same time, existing research on the use of terrorism in civil wars primarily focuses on domestic factors, thus overlooking the impact of external shocks such as the deployment of PKOs. We argue that PKOs can have critical unintended consequences inducing tactical adaptation in rebel violence as they alter the government-rebels balance of power. Particularly, rebel groups that are militarily strong prior to the UN arrival are incentivized to escalate terrorist violence to overcome the physical barrier imposed by PKO forces and improve their bargaining position vis-a-vis the government. Weaker groups, which in the absence of PKOs are more likely to use terrorism, have not only limited capacity but also fewer incentives to escalate terrorism when PKOs deploy. Leveraging new disaggregated data on rebel terrorist attacks during civil wars, we provide the first global actor-level analysis of the relationship between PKO deployments and changes in rebels' tactical preferences for terrorist violence. We find that, conditional on initial government-rebels power relations, PKOs can make terrorism the weapon of the strong. Our study sheds light on the unintended effects of peacekeeping, the causes of terrorism, and offers important policy implications for several current PKOs deployed in the midst of violence.