Legal constants for ensuring national security in the context of the crisis in international relations

This article examines the fundamental legal principles − the ‘constants’ that underpin the functioning of the state as the guarantor of national security in conditions of international tension, armed conflict, and the undermining of the global legal order. The article identifies the legal principles that must remain in force even in a state of emergency, such as public interest, the rule of law and the constitutional duty to defend the state. The article analyses the problems arising from the deformation of international law and violations of the principles of sovereignty and the inviolability of borders, as well as the transformation of the internal legal order under the influence of external threats. The article provides a comprehensive scientific analysis of the key legal principles that determine a state’s institutional capacity to ensure national security amid crises in the international legal order. Focusing on the Constitution of Ukraine, the study examines provisions that remain inviolable during martial law, such as the protection of sovereignty and territorial integrity (Article 17), the rule of law (Article 8), the legality of public authority actions (Articles 6 and 19), and the prioritization of public interest in times of threat (based on the Constitutional Court of Ukraine’s practice). The article argues that these provisions form the legal core that guarantees the stability, predictability, and legitimacy of public administration in extreme circumstances. In the context of modern public law theory, the stabilizing, legitimizing and integrating functions of legal constants are revealed. Considering the academic contributions of V.B. Averianov, O.F. Andriiko, O.V. Skrypniuk, S.V. Golovaty, Yu.S. Shemshuchenko, I.V. Lutsky and other scholars, the author presents a theoretical model of the state’s legal response to threats. This model encompasses legal certainty, institutional continuity, and the accountability of the executive branch. The author emphasizes that, in wartime, law performs regulatory, guaranteeing, mobilizing and value-oriented functions. Particular attention is paid to analyzing the doctrinal approach to public interest as a criterion for the legitimacy of restrictions on constitutional rights. The author formulates conclusions regarding the need to maintain the internal legitimacy, legal continuity and organizational accountability of the public administration system in conditions of existential threat.