The introductory chapter presents the key arguments of the book. It problematises the assumption, shared in Western military and academic circles, that winning over the population’s hearts and minds constitutes a universal recipe for victory in counterinsurgency (COIN) warfare. Engaging in theoretical debates on the nature of COIN warfare, this chapter demonstrates that the logic and mechanisms of brutalisation-centred COIN campaigns remain heavily underexplored. This chapter explains why it is important to strengthen our understanding of the results achieved by counterinsurgents following the brutalisation paradigm. It then concludes by providing a detailed overview of the data and methods employed throughout the book.