While significant scholarly work has been dedicated to the institutionalization of the European External Action Service (EEAS) and its role in shaping the European Union’s (EU) foreign policy goals, less attention has been given to the Service’s wider competencies and agenda-setting power in the case of the Common Security and Defence Policy. This article aims to assess the growing role of the EEAS in defence and in spearheading new ways of bridging foreign policy and security in a comprehensive manner. In doing so, the research explores how the security and defence dimensions were incorporated into the EEAS, by examining the processes of institutionalization in the EEAS crisis management structures in the post-Lisbon context, and by zooming in on the intergovernmental and supranational dynamics in the European security and defence architecture. The article finds that continued organizational innovation and the reinforcement of supranational mechanisms in the EEAS and the European Commission have had a positive impact on the EU’s security and defence, representing a step further in bridging the foreign policy, security and defence divides at the EU level.