The Russian invasion of Ukraine in February 2022 has exposed the critical state of the European Union’s defence and security strategies. At the same time, the EU’s Strategic Compass outlined a vision for greater defence integration, long-standing divides among member states persist, hindering coherent action. The initial unified response to Russia’s aggression has faded into a strategic divergence, with contrasting national priorities. The prospect of a Trump administration in 2025 exacerbates Europe’s security vulnerabilities, as Ukraine remains heavily dependent on US military aid. The failure to prepare for a US withdrawal leaves the EU strategically paralysed, risking both Kyiv’s sovereignty and Europe’s future security. This study explores the consequences of this strategic void and underlines the importance for the EU to develop a unified defence strategy.