The Conceptual Background Paper provides academic reflections on Europe’s resilience and a (re)invigorated EU enlargement and neighbourhood strategy. It first outlines the milestones of the EU’s policies with its neighbourhood. A guiding question is whether and if so in how far the EU’s enlargement policy can live up to its reputation of being one of the EU’s most successful foreign policies again – a label that has seemed too ambitious for the past two decades in view of the countries in the Eastern Neighbourhood and Western Balkans. Subsequently, the concept of resilience is introduced and critically assessed in the context of EU foreign policy. The InvigoratEU Triple-R-Approach: Reforming, Responding, Rebuilding guides the remaining part of the study, in which the challenges and potentials of EU enlargement and neighbourhood policies will be assessed. These will be analysed in terms of contribution to democratic consolidation, conflict prevention, capacity-building, enhancing security and the protection against hybrid threats and potentials for connectivity and sustainable (social and economic) development.