The intricate interplay between food, energy, water, societal dynamics, and the environment constitutes the bedrock of contemporary global challenges. In recent decades, this convergence has emerged as a focal point for scientific inquiry, policy formulation, and societal discourse. This book seeks to meticulously unravel the complexities inherent in this nexus, shedding profound light on the interconnected risks, vulnerabilities, and transformative opportunities that define our quest for sustainability in the twenty-first century. The materials of this book were prepared mainly by authors working on the joint project between the International Institute for Applied Systems Analysis (IIASA) and the National Academy of Sciences (NAS) of Ukraine “Integrated robust modeling and management of food-energy-water-land use nexus for sustainable development”, and on the project “Comprehensive analysis of robust preventive and adaptive measures of food, energy, water, and social management in the context of systemic risks and consequences of COVID-19” (0122U000552) of the NAS of Ukraine. Members of the System Analysis Committee of the NAS of Ukraine were also involved in the preparation of book chapters. The authors dedicate this book to the memory of the Academician of NAS of Ukraine, Professor Yuri Ermoliev, who died in October 2022 and made a fundamental contribution to stochastic optimization as a basic tool for quantitative risk management. This book largely follows his ideas about risk management and its applications.