The article examines the theoretical and legal foundations as well as practical mechanisms of the European Union’s influence on the reform of law enforcement systems in EU Member States in the context of Ukraine’s European integration processes. It analyzes the evolution of Ukraine’s European integration course and the intensification of reforms after 2014 and in the context of the full-scale invasion, which has significantly strengthened the security dimension of integration and public support for these changes. The regulatory and legal framework of EU requirements for law enforcement systems is systematized through the prism of the EU primary law, in particular the Treaty on European Union (TEU), the Treaty on the Functioning of the European Union (TFEU), and the Charter of Fundamental Rights of the European Union. It is determined that the EU does not unify the structure of law enforcement agencies in Member States but establishes supranational standards for their functioning, based on the principles of the rule of law, political neutrality, independence of the judiciary and prosecution, respect for human rights, and effective democratic oversight. The content of key provisions of EU primary law and their impact on the organization and functioning of law enforcement bodies are examined, particularly in the areas of cross-border cooperation, information exchange, joint crime and terrorism prevention, and the provision of procedural human rights guarantees. It is substantiated that the effectiveness of law enforcement systems in the EU is assessed not only by crime-fighting outcomes but also by the level of respect for fundamental rights and freedoms. A comparative analysis of the implementation of European standards in Poland, Hungary, and Slovakia is carried out. The key areas of criticism by EU institutions are summarized, including the politicization of the prosecution service, weakening of judicial independence, excessive expansion of law enforcement powers without adequate oversight, and violations of human rights. It is determined that deviations from EU standards are accompanied by the application of political, legal, and financial instruments of influence, including infringement procedures and restrictions on access to funding. Based on the analysis of European Commission reports and the application practice of the EU Charter of Fundamental Rights, the most problematic areas in Member States are identified, particularly judicial independence, the functioning of prosecution services, the proportionality of police powers, and the protection of migrants’ rights. The existence of regional differences in the level of compliance with EU standards is substantiated.
Oleksandr Olkhovskyi (Fri,) studied this question.