Since the late 1990s, a number of new and actualised words and set expressions with the component war in their structure have appeared in the Russian-language mass media. For instance, we can give such linguistic units as examples: proksi-voyna/proksivoyna/proxy-voyna / English proxy war; kvazivoyna / English quasi war; kibervoyna / English cyber war; myatezhevoyna/myatezh-voyna / English insurgency; nedovoyna / English sub-war; para-war/para-voyna; poluvoyna / English semi-war; postvoyna / English post-war; gibridnaya v. / English hybrid war; setevaya v. / English network war; mentalnaya v. / English mental war; oposredovannaya v. / English proxy war; v. po dogovorennosti / English war by arrangement/proxy war; v. chuzhimi rukami / English proxy war, and others. The process is due to significant changes in the theory and practice of modern warfare and is primarily influenced by the English language. As a result, the basic meaning of war, i. e. ‘an armed struggle between states, nations, or social classes; military action’, has undergone some semantic widening. The article describes in detail the new English borrowing proxy war, as well as a few other new loanwords and derivatives formed from the word war and actualised lexemes with this component. The novelty of the study consists in the presentation of lexemes relevant in media discourse. They contain the word war in their composition, are related to the topic of modern interstate conflicts, and are not codified in dictionaries. The relevance is determined, on the one hand, by the high demand for these naming units in Russian-language mass media, and on the other hand, by the lack of their systematic linguistic description. The article aims to identify the range of words (containing the component war in their structure) significant for the Russian-language military and political discourse of the first twenty years of the 21st century. The other goals are to determine the mechanism of their appearance in the Russian language and characterise the semantic and stylistic features of these units. The paper draws conclusions about the role of English borrowing and actualisation in this process. Lexemes with the evaluative prefixes nedo-/sub-, polu-/ semi- and the initial components kvazi/quasi..., polu/half...) actualised in the modern extra-linguistic and linguistic context are members of the relevant word-formation patterns. The new anglicism proksi-voyna/proxy war is the semantic centre of this group. It indirectly, through the initial component proksi-/proxy-... in the meaning ‘relating to a proxy war, participating in its conduct’, influences the expansion of the vocabulary group associated with the new modern stage of interstate conflicts. Individual naming units have semantic doublets in the form of compound names. They also semantically converge with vocabulary outside this group. Changes in the semantics of the word war occur due to the loss of some features (an obligatory armed conflict, the absence of the conflict initiator on the enemy’s territory since the goal is to bring the enemy under control rather than to eliminate them, and so on) and the emergence of new ones (the use of new technical means, techniques, etc. of putting pressure on the enemy). The research material was obtained from the Integrum database, Google and Yandex resources. The study used classification in conjunction with descriptive, comparative, and componential analysis.