The article discusses selected theoretical and practical problems of the ongoing Russian Ukrainian war since 2014 from the perspective of Carl von Clausewitz’s political theory of war. It argues, first, that defining the first phase of the conflict as “hybrid war” on theoretical grounds is an unnecessary exercise that obscures the methodologically important difference between war and peace. Second, despite technological innovations, the concepts of “fog of war” and “friction” remain relevant. Third, the current phase of the conflict shows that the spontaneous and grassroots involvement of citizens in the war was a transitional phenomenon that became subordinated to central command structures. It also shows that from the perspective of Clausewitz’s theory, Russia’s strategic failure in the first part of the second phase of the conflict is completely understandable.