When states want to engage in conflict prevention and peacebuilding they often act through the framework provided by international organisations. International organisations, such as the EU, UN and OSCE, have mechanisms and instruments in place to react to conflicts and engage in post-conflict reconstruction. Scholars have extensively studied why and how international organizations deploy operations, such as the 30+ CSDP missions. Yet they have insufficiently analysed the mechanisms through which states make civilian capabilities available. This is critically important, as an under-resourced mission is unlikely to succeed in its objectives. Through a comparative analysis with the UN and the OSCE, this paper sheds light on how the EU deploys civilian capabilities for conflict prevention and peacebuilding. It focuses on the procedures in Brussels, including in the European External Action Service, to better understand the effectiveness of EU conflict prevention and peacebuilding.