Visas and Walls

Borders traditionally served to insulate nations from other states and to provide bulwarks against intrusion by foreign armies. In the age of terrorism, borders are more frequently perceived as protection against threats from determined individuals arriving from elsewhere. After a deadly terrorist attack, leaders immediately encounter pressure to close their borders. As Nazli Avdan observes, cracking down on border crossings and policing migration enhance security. However, the imperatives of gl