The seminar deals with the evolution of the EU’s Common Security and Defence Policy (CSDP) from its inception in 1998 to the present day, in the shadow of the war in Ukraine. Using the theoretical framework of historical institutionalism, Professor Koppa examines both the successes and failures of the CSDP. Drawing on a series of interviews with officials and researchers from various EU institutions, NATO, and diplomatic missions of EU member states, she assesses what has instigated changes in the CSDP, and why some events have proven more determining and influential than others. The presentation reviews several crises that have shaped the CSDP, including the Yugoslav Wars, the Second Gulf War, the Libyan campaign, the Ukrainian crisis, the Syrian crisis, Brexit and the current war in Ukraine in order to understand how real-life events have influenced policy.