The Complementary Role of NATO and the EU in the Transformation of Regional Security in the Western Balkans

This study aims to examine the role of internationally influential organizations, in facilitating the development of security regimes and paving the way for the establishment of security communities in post-conflict regions, with a specific focus on the Western Balkans (WB). In this context it explores the complementary roles of the European Union (EU) and the North Atlantic Treaty Organization (NATO) in promoting regional stability and peace in an area historically characterized by ethnic tensions, political volatility, and the enduring consequences of conflict. NATO’s role centers on military engagement, collective defense, crisis management, and defense sector reform, pillars of hard security, whereas the EU emphasizes political and economic integration, rule of law reforms, institution-building, and socio-economic development to address the structural causes of instability. The study argues that both organizations, primarily through their membership conditionalities, have played pivotal roles in transforming the WB from a conflict formation into a functioning security regime, thereby laying the groundwork for a potential security community. Guided by Regional Security Complex Theory (RSCT) and employing a process-tracing method, the research addresses the central question of “how have the EU and NATO policies contributed to the transformation of the WB from a historically conflict-prone region to a region of increasing peace and stability over the last three decades?”.