In 2014, Russia's actions in Ukraine were based on the concept of “hybrid war” which is - from the structural and functional points of view - unique in many ways. The form of war is “hybrid” however the content is “asymmetric,” which means: war between belligerents whose relative military power and strategies/tactics differ significantly. Most clearly the nature of this type of war was demonstrated by the annexation of Crimea. Later this intervention was followed by Russian support to local radical elements in Donbass and a full-scale invasion of Russian troops in Eastern regions of Ukraine, which the Kremlin still doesn't acknowledge. Although the nature of each specific element of this “hybrid war” is not new and has been used in almost all the wars of the past, what is unique is the coherence and interplay of all elements, the dynamism and flexibility of their use and the paramount importance of the information factor. Moreover, the information factor became an independent component of its own and is no less important than military actions. Moscow's intervention in Ukraine has demonstrated that Western policymakers from EU and NATO need to take these factors into account when crafting new concepts and re-examining existing strategies aimed to maintain the European borders unchanged and secure.