The article examines the legal nature of the so-called Ukraine-related sanctions in terms of the law of international responsibility. The author concludes that the measures taken by a number of Western countries against Russia in connection with the events in Crimea and Eastern Ukraine, as well as the reaction of Russia to those measures, by their legal nature and content are not ‘sanctions’ in the understanding and in the context this term is mainly used in the modern law of international responsibility. The first part provides a brief description of the so-called Ukraine-related sanctions and the Russian response. The second part is devoted to the definition of the terms themselves. The author concludes that it is more preferable to use the term ‘countermeasures’ describing unilateral measures in the law of international responsibility. The third part examines the lawfulness of countermeasures taken by a State other than an injured State. The Conclusion contains an attempt to assess the legal nature of Ukraine-related sanctions on the basis of the study of international law and practice.