With funding from the Swiss Federal Department of Foreign Affairs (FDFA), this research aims to examine the operationalization of the Nexus approach, as defined in the Organisation for Economic Co-operation and Development - Development Assistance Committee (OECD DAC) recommendations on the Nexus (OECD, 2019), in five case studies, namely Libya, Iraq, Cameroon, Somalia and Afghanistan. The aim is to examine if and how the Nexus approach has been operationalized in these fragile and conflict-affected contexts, as well as the approach's implications for principled humanitarian action (PHA).While the global policy discussions on the Nexus have remained somewhat theoretical, this research aims to bring practical field examples, good practice and lessons learned to the table to inform evidence-based decision-making on the advancement of the Nexus.