Russia’s ‘special military operation’ in Ukraine is an opportunity for readdressing a crucial theoretical question: How to understand the role of hypernationalism in the run-up to war? Given the participation of Ukrainian ultranationalist militias and Russia’s goal of de-Nazifying Ukraine, a need emerges to provide a greater understanding of hypernationalism and its relation to this war’s origins. By going back to John Mearsheimer’s 1990 article ‘Back to the future: Instability in Europe after the Cold War’, this article examines Mearsheimer’s idea of hypernationalism and the problem of how states can signify other nations most negatively in the run-up to war. Drawing on a problem-driven strategy, it tackles this problem by applying ‘Essex School’ poststructuralist discourse theory. It argues that Ukrainian hypernationalism played a vital role in the genesis of this war, although not as a stable set of principles that possess a causal force but as a political subjectivity that the Russian government signified as a threat to its national identity. I use this distinction to theorise the role of hypernationalism by examining Russian official statements about Ukrainian neo-Nazism.