Today the United Nations begins convening a two-day high-level meeting on peacebuilding and sustaining peace to assess efforts undertaken and opportunities to strengthen the UN’s work. Prevention—emphasized by Secretary-General António Guterres in his first address to the Council in January last year—is at the top of the agenda. The human and economic costs of managing conflict have reached levels that are overwhelming the international system; the number of wars has more than tripled since 2010, and the global humanitarian appeal in 2017 was a record $23.5 billion.