“Taming the Storm” of Hybridity: The EU-NATO Relationship on Countering Hybrid Threats - From Functional Overlap to Functional Cooperation

This paper investigates why relations between the European Union (EU) and NATO in countering hybrid threats have been characterised by cooperation rather than rivalry. By examining the onset and development of the EU-NATO functional overlap in this policy area, the paper explains the factors driving their functional cooperation. Using an eclectic approach that integrates institutional overlap theory and considers both systemic factors (international shocks) and unit-level factors (resource dependence), this research reveals how cooperation has evolved. A key focus is the role of informal relations and the pivotal function of the European Centre of Excellence for Countering Hybrid Threats (Hybrid CoE) in facilitating this cooperation. This paper makes two original contributions: first, it addresses an empirical gap in the literature by providing a theory-driven analysis of EU-NATO interactions in countering hybrid threats, and second, it contributes to broader discussions on interorganisational relations. This research identifies three key findings. First, the shift in the international security environment following Russia’s 2014 invasion of Crimea was instrumental in prompting both the EU and NATO to prioritise countering hybrid threats, leading to a functional overlap. Second, this overlap fostered cooperation rather than conflict, as both organisations recognised their mutual reliance on one another’s resources to address hybrid threats effectively. Third, the creation of the Hybrid CoE emerged as a critical factor in managing and supporting the EU-NATO functional overlap by increasing the frequency and depth of interactions between the two organisations and by enhancing informal relations. These findings highlight the significance of exogenous shocks, resource-driven cooperation, and informal relations in fostering EU-NATO cooperation in the realm of countering hybrid threats.