This book connects the scholarly discussions on 'security' and 'resilience', by examining the various definitions and meanings of the terms in the EU's Eastern Partnership (EaP) policy, and in what ways the EU has attempted to define the relationship between security and resilience in its official rhetoric and in policy practice. The Russian invasion of Ukraine in February 2022 has largely been viewed as an extraordinary resilience test for the EU. The war has unleashed multiple crises ranging from security and asylum to energy and the economy, in turn raising questions not only on how the EU can ensure the resilience of its eastern partners, but also questions existential to the EU, such as institutional and policy reform, further EU enlargement and the EU's role in a rapidly changing global context of polarisation and fragmentation. The chapters in this edited volume draw on a diversity of original conceptual and theoretical frameworks that are combined with an empirical analysis of often overlooked dimensions of EU’s policy towards the EaP countries, drawing on the original data collected by the authors, including the semi-structured interviews. In light of the aforementioned challenges, the chapters to this book have only increased in relevance, pointing to pathways and opportunities for the EU to strengthen the resilience of its eastern partners and its own resilience in the future, and inviting policy-makers and scholars to reflect on potential pitfalls, contradictions and limitations of EU resilience-building. This book will be beneficial to students, scholars and academics interested in European Studies, Politics and International Security. The chapters in this book were originally published in the Journal of Contemporary European Studies.