The dissertation offers a thorough study of the key shifts in diplomacy brought about by the Russo-Ukrainian war, with regard to their paradigmatic significance for the development of diplomatic practice. The full-scale aggression of the Russian Federation against Ukraine has generated not only a crisis of international security but also a profound transformation of diplomacy as an institution of global governance, since the war has exposed the structural limitations of the liberal order and made pressing a transition to minilateral coalitions. Diplomacy thus evolves from a form of reconciling state positions into an instrument for implementing coalition decisions: it coordinates the sanctions regimes of the EU and the G7, integrates Ukraine's defence-industrial base into Western logistical chains, and formalises evidentiary procedures. Accordingly, this study acquires fundamental significance for rethinking contemporary theory and practice in international relations.
The first chapter conceptualises diplomacy as a multidimensional and historically variable phenomenon; it analyses the competition between classical and contemporary theoretical approaches – from the instrumentalist treatment of diplomacy as a derivative of state power to its understanding as a dynamic, discursive, and performative practice of constructing international order – and underscores the ambivalence of its functions – from peaceful mediation to the entrenchment of dominance. The second chapter analyses the impact of the 2014–2021 aggression and the full-scale invasion of 2022 upon the logic of international interactions; it examines "diplomatic mobilisation" and the emergence of a conditional "diplomacy of direct action", and substantiates Ukraine's transformation from an object into a subject shaping the contemporary international order. The third chapter concentrates on the reinterpretation of the normative foundations of diplomacy amid the emergence of a hybrid order, of "divided multilateralism", and of the so-called "evidentiary turn", which converts analytical competences and control over information into sources of legitimate power.
The scholarly novelty of the results lies in the fact that, for the first time in Ukrainian political science, the thesis is substantiated that Russian aggression became a catalyst for the operationalisation of diplomacy, prompting a transition from universalist multilateralism to flexible minilateral coalitions oriented toward concrete security outcomes. Sanctions policy, legal mechanisms of accountability, and defence-industrial coordination are shown to have formed a new architecture of deterrence, within which economic, legal, and military-technological instruments are integrated into a single strategy of long-term influence. The phenomenon of Ukraine's "diplomacy of direct action" is conceptualised as an innovative model of foreign-policy practice combining public mobilisation, moral argumentation, digital instruments, and network coordination with traditional intergovernmental interaction; it is argued that Ukrainian practices (parliamentary diplomacy, semantic securitisation, twiplomacy, intellectual-diplomatic outsourcing) fostered a hybrid paradigm of "total diplomacy".
The historical evolution of diplomacy is specified as a permanent yet structurally heterogeneous practice; its ambivalent character is demonstrated in the combination of cooperative and hierarchical logic, while the shift from "old" to "new" diplomacy is shown to reflect a change in the types of international order that preserves its fundamental function of managing stability. Diplomatic studies within political science are advanced: through the systematisation of competing theoretical traditions (realist, liberal, constructivist, and critical), diplomacy is shown to be a multidimensional, historically variable, and contextually conditioned phenomenon admitting of no unified definition. The understanding of diplomacy is deepened as a practice in which military deterrence, economic coercion, legal accountability, and defence-industrial cooperation together perform functions that classical theory ascribed to separate specialised institutions.
The practical significance of the results consists in the possibility of their application for research, applied, and educational purposes: in the work of state bodies and non-governmental organisations engaged in shaping and implementing Ukraine's foreign-policy priorities, and in the design of courses in diplomacy, international security, and foreign policy for the specialties "International Relations" and "Political Science", as well as in the training of diplomats and civil servants.
