Two decades after the fall of the Berlin Wall, why are the notable democracies of the United States, India, and Israel building massive walls and fences on their borders? Despite predictions of a borderless world through globalization, these three countries alone have built security barriers totaling an astonishing 5,700 kilometers in length. In this groundbreaking work, Reece Jones analyzes how these controversial walls were justified, their impact on those living behind them, and the long-term effects of the hardening of political boundaries. Border Walls is a bold, important intervention that demonstrates that the exclusion and violence necessary to secure the borders of the modern state often undermine the very ideals of freedom and democracy the barriers are meant to protect.