Peacebuilding thinking and practice have evolved significantly over the past decade. The business case for the effectiveness of peacebuilding has been established. Successful interventions underscore the importance of peacebuilding initiatives, as do the high-profile failures that occur when peacebuilding is absent, fragmented or insufficient. With the emergence of new approaches to peacebuilding led by the United Nations Peacebuilding Architecture Review, this paper examines the state of peacebuilding operations and finance in fragile contexts and, building on established trends and debates, identifies four areas that could be critical for driving progress on peacebuilding over the next decade. The paper is one of ten working papers supporting States of Fragility 2020. Together with the papers entitled "Diplomacy and peace in fragile contexts", "Conflict prevention in fragile contexts", and "Security actors in fragile contexts", It provides a comprehensive background to Chapter 2 on peace in States of Fragility 2020.