UN peacekeeping upon deployment: Peacekeeping activities in theory and practice

United Nations peacekeeping operations (UNPKO) have been deployed in conflict-affected countries for decades. While we thoroughly understand what UNPKOs are mandated to do, there is little research on what activities peacekeepers actually do upon deployment in their host countries and in which sequence, if any. To address this gap, we formulate descriptive hypotheses about the number of implemented peacekeeping activities, the expansion toward new activity categories, and the sequencing of implemented activities. We use the novel Extended Peacekeeping Activity Dataset to evaluate our theoretical expectations for all UNPKOs deployed after the end of the Cold War until 2017. Our findings show that UNPKOs implement more activities over time. Yet, the expansion of UNPKOs’ activities into new activity categories by generation (second, third, and stabilization) is not as clear-cut in practice as expected. Instead, there is a notable expansion of activities within activity categories—especially during third-generation UNPKOs. Finally, we find a security-first sequencing for second- and third-generation UNPKOs, while stabilization UNPKOs implement a high share of security activities long after initial deployment.