This paper examines the changing role of the European Border and Coast Guard Agency (Frontex) in the context of the Ukraine and Moldova accession effort to the EU, with a focus on the lessons learned from recent migration crises. The article uses these two very different instances as case studies: the instrumental hybrid crisis on the EU–Belarus border and the largest refugee crisis in post-war Europe created as a result of Russia’s aggression in Ukraine in order to analyze how these incidents have changed Frontex’s mandate, operational capabilities, and strategic importance. The main research question of this thesis is how the experiences of the hybrid border crisis on the EU–Belarus border and the refugee crisis following the Russian invasion of Ukraine have changed the role of the European Border and Coast Guard Agency (Frontex) in the accession process of Ukraine and Moldova. Based on the securitisation theory, the paper applies the content-analysis method to study the EU border security strategy and risk-analytical sources, communications relating to EU enlargement, country reports, expert interviews, and comparative case analysis. It argues that the two crises have revealed that the management of the EU’s external borders was fundamentally flawed, and at the same time, they played a key role in the rapid transformation of Frontex from a mere executive agency to a proactive, geopolitically resilient instrument on the Union’s Eastern flank. Key findings highlight Frontex’s rapidly expanding pre-accession engagement: in Ukraine through a €12 million capacity-building grant (2023) and cooperation with EUAM Ukraine, and in Moldova via the status agreement (effective November 2022) enabling joint operations and the deployment of over 100 officers by September 2025. The analysis concludes that targeted Frontex support encompassing technical assistance, training, information exchange, and joint operations has become a critical enabler of Ukraine’s and Moldova’s alignment with Schengen standards and of mitigating spillover risks to the current EU external border. Successful integration, however, requires sustained political commitment, respect for fundamental rights, adequate funding, and enhanced coordination across EU instruments. On the other hand, these changes reflect the broader shifts in European policy and the understanding of regional security, which lead not only to changes in foreign-policy priorities, but also to a redefinition of the EU’s own role, its strategic priorities, and the overall architecture of regional security.
