When in 1989 the Berlin Wall fell, and South African apartheid soon followed, it appeared even to political realists of the period that such systems, with their landscapes of walls and practices of separation, would rapidly be consigned to historical memory. In one of the great ironies of recent history, however, a new generation of such landscapes is proliferating in the wake of 1989, used by practitioners of power to promote systems of segregation and control movements of groups designated as threats by virtue of their representation as “other.” Reflecting collective psychologies of fear, these environments range from urban-based gated communities, where class prejudices against the poor and apprehension about crime coalesce in “fortified enclaves” within Cities of Walls, to borderlands between nation–states where hostility to immigrants and prejudices against ethnic others converge in creating what scholars describe as The Wall Around the West. Despite differences, these landscapes share a similar aim: they use built environments as defensive fortifications to preempt the circulation of people across territorial space based on class, religious, and ethnic divides. In this way, gated communities in São Paulo and Los Angeles, the walled borderlands of Melilla and Ceuta separating the European Union from Africa, and the walled border of Operation Gatekeeper separating the United States from Mexico, are broadly comparable.