Natural resources are increasingly at risk due to climate change, demographic pressure and economic growth, political instability and forced migration. Globalisation places additional strain on the resources, biodiversity and ecosystems and, through them, on the economies and well-being of populations of affected and neighbouring countries. While approximately 2.2 billion people around the world still lack safely managed drinking water, 789 million people lacked electricity in 2018 and an estimated 25.9 percent of the global population - 2 billion people - were affected by moderate or severe food insecurity in 2019. It was in this context of water, energy and food constraints that, in 2018, the European Commission's Joint Research Centre (JRC) in partnership with UNESCO's Intergovernmental Hydrological Programme (IHP) launched the project "Water-Energy-Food-Ecosystems (WEFE) Nexus: Analysing solutions for security supply". The WEFE Nexus aims to increase water, energy, food security without compromising ecosystems services. Its components are present in 14 of the 17SDGs and are therefore highly relevant in terms of working towards their implementation.This publication compiles a number of case studies with the aim of highlighting the importance and benefits of the WEFE Nexus approach for development cooperation. It identifies pathways for a more integrated and sustainable use of resources that goes beyond traditional sector-specific development silos.