In Subversion, Lennart Maschmeyer provides a powerful new theory and analysis of an age-old concept. While a strategy of subversion offers great strategic promise in theory, it faces an underappreciated set of challenges that limit its strategic value in practice. Drawing from two major cases—the KGB's use of traditional subversion methods to crush the Prague Spring in 1968 and Russia's less successful use of cyberwarfare against Ukraine since 2014—Maschmeyer demonstrates both the benefits and weaknesses of the approach. While many believe that today's cyber-based subversion campaigns offer new strategic opportunities, they also come with their own challenges. Because of these disadvantages, cyber operations continue to fall short of expectations—most recently in the Russo-Ukrainian war. By showing that traditional subversion methods remain the more potent threat, Subversion forces us to reconsider our fears of the subversive potential of cyberwar.