This book seeks to answer the question: What have been the characteristics of the UN's participation in the formation of the National Policy for Social and Economic Reincorporation in Colombia (2016-2018)? The book seeks to answer the question of what have been the characteristics of the UN's participation in the formation of the National Policy for Social and Economic Reincorporation in Colombia (2016-2018)? This research topic was born out of the gap that exists in the current literature. This research is interested in characterising the participation of the United Nations (UN) in the formation of the National Policy for Reincorporation, with the purpose of contributing from Political Science to the understanding and improvement of the tools used in the analysis of National Peace Policies, and in their formation process in Colombia, which have counted or have international actors.