Peacekeeping and the Enforcement of Intergroup Cooperation: Evidence from Mali

Despite the abundance of evidence that peacekeeping works, we know little about what actually makes peacekeepers effective. Recent work suggesting that local agendas are central to modern conflicts make this omission particularly problematic. The article demonstrates that the presence of peacekeepers makes individuals more optimistic about the risks of engagement and the likelihood that members of out-groups will reciprocate cooperation. I use data from a lab-in-the-field experiment conducted in Mali, a West African country with an active conflict managed by troops from France and the United Nations (UN), to show that UN peacekeepers increase the willingness of individuals to cooperate relative to control and French enforcers. Moreover, I find that UN peacekeepers are especially effective among those participants who hold other groups and institutions in low esteem, as well as those who have more frequent contact with peacekeepers. Follow-up interviews and surveys suggest that perceptions of the UN as unbiased rather than other mechanisms account for its effectiveness.