In The EU and the Security-Development Nexus, Hans Merket unravels the long-standing commitment of the European Union (EU) to integrate its policies across the security-development nexus. By fine-tuning the Common Foreign and Security Policy (CFSP) – which includes the Common Security and Defence Policy (CSDP) – with its development cooperation policies, the EU aims to end the devastating vicious cycle of insecurity and poverty in fragile states. This book undertakes a comprehensive analysis of the EU’s words and deeds that result from this engagement across its entire policy, and its institutional and legal system. This gives a complete picture of the significance, impact, limits, potential and remaining challenges of this policy commitment, and simultaneously elucidates the practical impact of Treaty reform in the area of EU external action.