Proceedings of the International scientific and practical conference ―Paris Science and Education Forum‖ (March 2-4, 2026) / Publisher website: www.naukainfo.com. – Paris, France, 2026. - 293 p.

85 State. While the international norm provides a common legal foundation, the mechanisms through which diplomatic protection is operationalized are shaped by domestic legal frameworks and law enforcement traditions. Within Ukrainian foreign diplomatic missions, internal security functions are performed by servicemen of the State Border Guard Service of Ukraine acting as duty commandants. Their activity represents a unique legal and operational interface between international diplomatic law and the domestic legal order of the host State. Although their authority is derived from Ukrainian legislation, its realization inevitably occurs within the jurisdictional environment of the receiving State. This dual legal positioning makes the role of duty commandants particularly sensitive to country-specific legal conditions. Their daily responsibilities – ranging from access control and incident response to coordination with local police authorities – are directly influenced by the procedural norms, evidentiary standards, and public order regulations applicable in the host country. Therefore, a comparative legal examination of this activity is necessary to understand the variability and structural features of diplomatic security practices across jurisdictions. Aim of the Study. The purpose of this paper is to analyze the legal status and operational functions of duty commandants in Ukrainian diplomatic missions through a comparative perspective based on differences in host State legal systems. The study aims to identify the key factors influencing the organization of security regimes, the limits of authority, and the patterns of cooperation with local law enforcement bodies in various countries. Materials and Methods. The research is based on a formal-legal analysis of international diplomatic law, particularly the Vienna Convention on Diplomatic Relations, as well as relevant Ukrainian legislation governing diplomatic service and the State Border Guard Service of Ukraine.