The article reveals challenges and prospects of Ukraine in the conditions of transitive world order crisis in Eastern European context. The issue of strengthening national security and protection of the territorial sovereignty of the post-Soviet countries and Eastern European countries in connection with the aggression of Russia and the occupation of part of the Ukrainian territories has been mainstreamed. The confrontation between Russia and the post-Soviet countries is a conflict of two civilizational systems, the struggle of two opposing worldviews and paradigms of a new world order. It has been proved that Russia’s Eurasian integration projects were aimed at attracting Ukraine and maintaining it in the sphere of Russia’s geo-economic and geopolitical influence. The creation of integration associations in the post-Soviet space is intended to become one of the instruments of revival of the Eurasian empire, in particular at the expense of the destruction of the national economy and the sovereignty of Ukraine. A key result of the Revolution of Dignity was the signing of the Association Agreement between Ukraine and the EU which destroyed Russia’s strategy to engage Ukraine in the Eurasian integration area. It is confirmed that after the Russian Federation’s unsuccessful actions to involve Ukraine in Eurasian integration structures through the use of managed pro-Kremlin power, Moscow abandoned this option and switched to a scenario under which the strategy of fomenting and supporting separatism in the south-eastern regions of Ukraine was implemented. The strategy to create a pseudostates on the territory of Ukraine in one way or another involves the issues of infrastructure and transit of Russian energy resources to the European Union. The formation of Novorossiya at the expense of Ukrainian sovereignty also included support from individual EU Member States to accelerate the construction of energy infrastructure bypassing Ukraine as a failed state. The annexation of Crimea became a non-standard geostrategic step in Russia, which led to the violation of the border of the sovereign state for the first time since the end of World War II. In general, the Crimea is an important sacred phenomenon and a geostrategic asset for the Russian Federation. Given the opening of new military bases in Belarus, the preservation of the Russian military contingent in Transnistria and the Donbas, as well as the creeping geopolitical displacement of Ukraine from the Black and Azov Sea, the latter automatically finds itself in a kind of geopolitical “garrotte” while losing access to the sea. In the end, Russian aggression aimed at destabilizing Ukraine also had internal political significance for Russia, since Europeanization of Ukraine and its political and economic success would become a new geopolitical trend and would call into question the effectiveness of the authoritarian regime of Russia and other post-Soviet countries. All this would become a clear example for the Russian society of the positive consequences of the democratic transformations of the great Orthodox state. However, while the Russian Federation has achieved some tactical advantages in Ukraine, thereby slowing its rapprochement with the EU and NATO, designing instability strategically prevents any involvement of Kyiv in Eurasian integration projects, further alienating it from Russia, making Ukraine more pro-Western and anti-Russian. Keywords: Ukraine, foreign policy, national security, Russian Federation, Eastern Europe, ODED-GUAM, Baltic-Black Sea Commonwealth