The article, employing the general scientific methodology of the systemic ap-proach as well as the results of empirical and theoretical research, examines the problem of the interrelation and mutual conditionality between war and the level of criminal illegality in Ukraine during the period of martial law. The purpose of the article is to clarify the essence of the phenomenon of rash-ism and to explain its negative impact on the state of crime in Ukraine during the Russian military aggression. It is substantiated that at the core of the Russian military aggression lies a specific ideology of the Russian state and society — the socio-political phenomenon of rashism, which is rooted in the ideologies of fascism and Nazism. A number of scholarly works by Ukrainian and Western researchers are analyzed, identifying the essential features and characteristic properties of fascism. Particular attention is given to Umberto Eco’s conception of fascism. The matrix of fascist fea-tures is applied to the modern Russian state and society, forming the basis for con-clusions regarding the presence of rashism in Russia. Using the systemichistorical method, the article demonstrates the evolution of the formation of fascist narratives in Russian society concerning Ukraine and the Ukrainian people. It reveals the his-torically conditioned aspiration of the inhabitants of the territory now occupied by the Russian Federation to enslave neighboring nations, to display unjustified ag-gression and cruelty, and to annex the territories of neighboring states — from the times of Kyivan Rus to modern Ukraine. Specific types of criminal offenses are identified, the spread of which in Ukraine has been caused both by Russian military aggression and by the phenomenon of rashism.