This article explores the relevance of Carl von Clausewitz’s theory in the context of contemporary nuclear warfare, analyzing how the concepts of friction, chance, and the duality of war apply to the strategic landscape of the 21st century. The research is guided by a central question: to what extent are Clausewitz’s theories, originally developed for conventional conflicts, still applicable to the analysis of modern nuclear war, with a particular focus on nuclear powers? The methodology employed is based on a comprehensive qualitative review of the literature, encompassing both Clausewitz’s classical works and contemporary studies on nuclear strategy and deterrence. Among the key sources are traditional interpretations of Clausewitz, such as On War (1984), and modern works addressing the evolution of nuclear strategy, including Lawrence Freedman’s studies on deterrence (2004) and Paul Bracken’s analysis of the new nuclear era (2013). These works provide the theoretical foundation to compare Clausewitz’s theories with current strategic challenges, such as the logic of mutually assured destruction. The findings indicate that, despite the transformations brought about by nuclear weapons, Clausewitz’s fundamental concepts remain relevant to understanding the dynamics of nuclear warfare. The concept of "real war" versus "absolute war" remains pertinent in the analysis of nuclear deterrence strategies, demonstrating how the threat of total destruction shapes both conflict and policy. Furthermore, the study reveals that friction and chance, central elements in Clausewitz’s theory, play a crucial role in the nuclear era, where uncertainty and the speed of decision-making can have severe consequences. It is concluded that Clausewitz’s theoretical framework remains useful for analyzing nuclear war, offering a robust conceptual structure to address the complexities of the contemporary global strategic landscape.