THE EU AND NATO FOLLOWING RUSSIA’S FULL-SCALE INVASION OF UKRAINE: THE TRANSFORMATION OF COMPLEMENTARITY IN THE EUROPEAN SECURITY ARCHITECTURE
Abstract
The article examines how the Russia-Ukraine war changed the European Union’s role in the transatlantic security system and the meaning of European strategic autonomy. Stronger cooperation between the European Union and the North Atlantic Treaty Organization is not treated as a sufficient result in itself. The study explains how autonomous EU instruments became connected with NATO-centred collective defence after 2022. It applies comparative document analysis, qualitative content analysis and process tracing to strategic documents, legal acts, implementation reports and academic studies published between 2016 and 2026. Particular attention is given to defence-industrial policy, military mobility and support for Ukraine. The article argues that the full-scale invasion did not end the Union’s search for strategic autonomy. Instead, it changed its function. Autonomy now refers less to separation from the United States or NATO and more to the capacity to create European financial, industrial, regulatory and logistical resources for defence within a wider transatlantic framework. The article introduces the concept of “embedded complementarity” to describe this model. It combines autonomous EU decision-making and instruments with their practical contribution to the European component of NATO-centred defence. The model is visible in strategic documents, industrial programmes, capability coordination, military mobility, training and long-term support for Ukraine. However, it remains incomplete because of separate planning systems, different memberships, political vetoes, fragmented defence markets and dependence on United States capabilities. The study concludes that the war became a catalyst for a substantial revision of EU security policy but did not create an integrated European defence order. Further research should assess the practical results of the new programmes after a longer implementation period.