The fall of the Berlin Wall in 1989 came to symbolize the dawn of a new era of openness and connectivity. Yet today, the world is ever more divided, demarcated, and - quite literally - fortified. We are living in a guarded age. Why and how has this happened? Where will it take us? In this book, David J. Betz explores the expansion of fortified physical infrastructure at every level of the global political economy. In cities, where security...