This article focuses on the investigation of the European Union's securitisation policy in the energy sector, in particular, the provision of energy carriers to the Union, which was developed in response to Russia's energy wars of 2006–2007 and 2008–2009 against Ukraine and indirectly against the European Union. The theory of securitisation, formulated by S. Ozkan, B. Buzan and other researchers, focuses not so much on eliminating the consequences of crises as on creating a system of securitisation for the relevant industries with increased stress resistance, diversification of economic and technological ties with partners and strengthening the social orientation of their functioning. The algorithmization of this policy and the changes that led to the institutional response to Russian aggression in the energy sector are investigated. The research is based on the approach of sociological (neo)institutionalism, which allows explaining political processes in terms of not only economic benefits, but also their importance for the development of other spheres of public life and international cooperation. This approach is based on the notion that, first, the institutional environment in which a particular institution operates provides it with the necessary resources, as well as legitimates and regulates its activities. As a result, sociological institutionalism emphasises the role of norms, rules, and culture, influencing the self-identification of actors associated with this institution, as well as defining „friends” and „foes” in the overall institutional structure. It is shown that changes in the EU energy policy are dictated not only by economic or technological considerations, but also by the requirement to meet the needs of the population and economy of the EU member states. At the same time, Ukraine's inclusion in the EU's common securitisation system is in the economic, political, and social interests of Ukraine, which, both under the Association Agreement and in the event of its accession to the EU, will have the status of an acceptor country. The article considers possible options for the EU and Ukraine to establish Ukraine as the EU's eastern securitizer and their respective consequences for both parties.