This report sets out to show how the UN can reinforce its utility and legitimacy in conflict prevention and mediation in a complex international environment. It draws on a series of case studies on conflict prevention for the NYU Center on International Cooperation (CIC)—including analyses of the Asia-Pacific, Latin America, Middle East and West Africa—which show how the UN’s engagement in the deterioration phases of a series of recent crises has prevented or reduced conflict, or at least has established a framework for later peace talks.