The volume examines the lessons learned and challenges identified during the almost two years of application of the Foreign Subsidies Regulation (FSR) by the European Commission, legal practice and contracting authorities, and places them in the context of an assessment of the FSR's conceptualisation, international reactions and the proliferating criticism in the academic literature. The contributions to this volume present the various challenges of the FSR through different lenses, thus providing a complex view of the FSR.