This thesis investigates the deepening trend of Nordic defense cooperation in light of the radically altered European security environment following Russia’s full-scale invasion of Ukraine in 2022. With Finland and Sweden’s memberships to NATO in 2023 and 2024, for the first time since the Kalmar Union the Nordic countries are fully allied, opening unprecedented opportunities for regional defense cooperation through both NATO and the Nordic Defense Cooperation (NORDEFCO). The research seeks to explain why the Nordic states, despite possessing relatively strong individual defense capabilities and existing alliance structures, are increasingly pursuing defense cooperation at the regional level. The research employs a qualitative content analysis of policy documents, ministerial declarations, and media releases, using a positivist framework to identify observable causal relationships and explanatory patterns. Four international relations’ theories—neorealism, small state theory, liberal institutionalism, and constructivism—are applied in parallel to assess their explanatory power. Neorealism highlights the role of shifting power balances and external threats, small state theory emphasizes shelter-seeking behavior and alliance reliance, liberal institutionalism underscores the centrality of multilateral frameworks, and constructivism brings attention to shared Nordic identity, norms, and values. The findings suggest that Nordic defense cooperation is driven by a combination of threat perceptions, structural constraints of small states, institutional opportunities, and normative alignment. NORDEFCO in particular has evolved from a cost-efficiency platform into a key complement to NATO and EU structures, functioning as both a regional security provider and a forum for strengthening Nordic unity. The thesis argues that understanding the phenomenon requires a multidimensional theoretical lens, as no single IR theory fully explains the complexity of the Nordic defense cooperation as a phenomenon. The study contributes to academic discourse on regional defense cooperation and provides timely insights for the ones interested in navigating the rapidly changing Arctic-Baltic security landscape.
Konsta Kovanen (Wed,) studied this question.