Zadorozhnii O. International Law in Relations between Ukraine and the Russian Federation.

The thesis is the first in Ukrainian science of international law comprehensive analysis of the international legal aspects of Ukrainian-Russian interstate relations from their genesis to the modernity. The author considers principal features, problems, trends and patterns of the transformation of international legal cooperation between Ukraine and Russia at all periods and in key areas, as well as the forms of their mutual influence. The features of the treaty and institutional mechanisms established for the regulation of bilateral relations during the post-Soviet years are distinguished. International legal positions of Ukraine and Russian Federation on all sensitive issues of relationships - from the "Crimean problem" to the delimitation and demarcation of borders have been analyzed. The main problems international legal relations between Ukraine and Russia are identified. The author puts emphasis on Russia's systematic violation of fundamental principles of international law and rules of international agreements; inequality of bilateral relations, enshrined in international treaties; lack of long-term vision of Ukrainian-Russian relations and the establishment of appropriate treaty and institutional mechanisms; refusal to apply international legal instruments on a systematic basis; secrecy, opacity, dependence of most important decisions on personal relations between leaders of states; minor role of institutional mechanisms; declaratory character of international treaties' provisions. The author conducted a legal qualification of the events of Russian-Ukrainian international armed conflict (2014 - 2015) and formed a holistic vision of international legal problems that arose due to the conflict. It is concluded that the Russian Federation is carrying out military aggression against Ukraine. Russia's acquisition of the Crimean peninsula (part of Ukraine's territory) through coercion or force constitutes annexation and actions of Donetsk and Lugansk regions - illegal military occupation. Generally, the Russian Federation has, since February 2014, violated every one of the ten basic principles of international law in its relations with Ukraine, systematically, in a clear and gross manner, as well as the rules of multilateral and bilateral international treaties. These actions in clear violation of international law are serious challenges to the rule of law around the world and should be a concern for all nations.