THE TRANSFORMATION OF THE EU COMMON SECURITY AND DEFENCE POLICY IN RESPONSE TO RUSSIA’S WAR AGAINST UKRAINE

Abstract

Russia’s full-scale invasion of Ukraine in February 2022 has profoundly reshaped the security environment of Europe and triggered a fundamental reassessment of the European Union’s role as a security actor. Traditionally characterized as a civilian and normative power, the EU has increasingly relied on instruments associated with military assistance and defence cooperation in response to the war. This shift has placed the Common Security and Defence Policy (CSDP) at the centre of the Union’s external action and raised important legal questions regarding the scope, limits and evolution of EU competence in the field of security and defence. The article examines the transformation of the EU’s CSDP in response to Russia’s war against Ukraine from a legal perspective. It argues that the changes observed since 2022 do not result from formal treaty amendment but rather from the reinterpretation and intensified use of existing legal instruments within the framework of the Treaty on European Union. By tracing the historical evolution of the CSDP from its origins under the Maastricht Treaty through its consolidation under the Lisbon Treaty, the article highlights the traditionally cautious and intergovernmental nature of EU security and defence cooperation prior to 2022. Particular attention is devoted to the legal significance of the measures adopted following Russia’s full-scale invasion, including the Strategic Compass for Security and Defence, the expanded use of the European Peace Facility and the establishment of the EU-led Military Assistance Mission in support of Ukraine (EUMAM Ukraine). The analysis demonstrates that these instruments have enabled the EU to provide unprecedented military assistance to a partner state while formally remaining within the existing treaty framework, notably the constraints imposed by Article 41(2) TEU. At the same time, the reliance on off-budget mechanisms and non-legally binding strategic instruments raises questions concerning accountability, coherence and democratic oversight within the EU legal order. The article concludes that Ukraine functions not as an exception but as a catalyst for a broader transformation of the CSDP. This transformation reflects a shift from a primarily crisis-management-oriented policy towards a more robust security role, with significant implications for the future development of EU security and defence law.