The impact of Ukraine's EU candidacy on the legal framework of EU enlargement

Abstract

This article explores how Ukraine’s candidacy for European Union (EU) membership has catalyzed significant institutional, procedural, and strategic innovations within the EU's enlargement policy. Traditionally characterized by legal rigidity and technocratic sequencing, the EU’s approach to enlargement has undergone a transformation due to the geopolitical urgency posed by Russia’s aggression against Ukraine. Through an analysis of key developments—such as the two-phase signing of the Association Agreement, the unprecedented acceleration of candidate status, early screening procedures, and the application of the revised enlargement methodology—this study demonstrates how the EU has adopted a more flexible, politically responsive model. It also examines the role of pre-accession integration and staged membership as tools for embedding Ukraine into EU structures before full accession. Ukraine's unique case has not only tested the resilience of EU institutions but has also redefined enlargement as a strategic instrument of foreign policy rather than a purely administrative process. The findings underscore that Ukraine is both a subject of enlargement and a driver of EU transformation, offering a blueprint for future candidate countries navigating complex geopolitical environments.