This volume explores four cases of integrated missions which have provided support to national SSR processes: the United Nations Mission in Burundi (ONUB), the United Nations Mission in the Democratic Republic of Congo (MONUC), the United Nations Stabilisation Mission in Haiti (MINUSTAH), and the United Nations Interim Administration Mission in Kosovo (UNMIK). Its aim is to examine the role and experience of UN integrated missions in SSR with a view to developing recommendations for future UN engagement in post-conflict SSR. The opening chapter briefly introduces the two key concepts used in this study, namely SSR and “integrated mission”, and provides an overview of the involvement in SSR of UN integrated missions in terms of mandates, activities and capacities.