This article analyses the challenges and perspectives of the European Union's security and defence policy in a new geopolitical era shaped by Russian aggression against Ukraine, growing US-China rivalry, and instability in the EU's neighbourhood. It identifies three key weaknesses that limit the Union's strategic autonomy: insufficient military capabilities, the fragmentation of the defence industry, and a reliance on external suppliers of weapons, equipment, and critical raw materials. Drawing on an interdisciplinary framework that combines political economy, political science, European studies, and security studies, the article examines how existing tools and initiatives, the EDF, PESCO, ASAP, EDIRPA, and the ReArm Europe plan, are responding to these deficits. While these instruments and initiatives demonstrate the EU's ambition to strengthen its security role, their effectiveness remains limited by political divergences and restricted resources. The author concludes that overcoming fragmentation and building sustainable mechanisms for defence cooperation are essential if the EU is to establish itself as a credible security actor in a multipolar world.