Border security is an obsession of our time. Why is this true and why does it matter? This book offers an in-depth look at border security in the US and worldwide after 9/11. It will appeal to students and researchers in political theory and international relations, and will interest policymakers and general audiences interested in the new security protocols that are proliferating worldwide.

Introduction; 1. Borders: thick and thin; Part I. The Perimeter: 2. The wall and its shadow: security in the borderlands; 3. Co-bordering: one border, two sovereigns?; 4. A global question: co-bordering, cosmopolitanism, and the spectre of empire; Part II. The Ports of Entry: 5. The tiniest constable: big data, security, and the politics of identification; 6. Sovereignty, security, and the politics of trust; 7. Into the digital dark: data, the global firewall, and the future of security.

'Beautifully written, Matthew Longo's book opens our eyes to the transformation of state borders in an era of new security technologies and big data. Longo's approach is rather unique in its combination of anthropological fieldwork and normative argument. His target audience is not any academic discipline, it is citizens who want to understand the new threats to their freedom, and do something about it too.' Rainer Bauboeck, European University Institute, Florence'Longo crosses disciplinary boundaries in order to make visible the complex realities of contemporary borders. This richly detailed and conceptually imaginative work provides a valuable critical perspective on a topic of growing importance in the modern world.' Joseph H. Carens, University of Toronto'Political theorists have expended much energy debating whether and how far states have the right to control movement across their borders, but have said little about what borders and border control might mean for the relationship between the state and its citizens. Matthew Longo offers a deep and powerful - and at times, disturbing - examination of this question in his important and timely study.' Chandran Kukathas, The London School of Economics and Political Science'Longo, an assistant political science professor at Leiden University, delivers a comprehensive study of the politics surrounding borders and border patrols, focusing on the technological advancement of and conceptual changes to security measures since 9/11. ... Longo's tone is urgent throughout, as when he writes, 'This is not simply a question of citizenship and sovereignty, but at core, the future of human rights protection in a data-centric world'. Longo outlines possible solutions as well as current problems, stressing the growing necessity of 'cross-border cooperation' between the US and Canada as well as between the US and Mexico, and proposing that neighbouring countries create 'collaborative zones' to accommodate migrants and refugees seeking safety. Longo's debut, complex and impressive in its scope, signals the emergence of an important political theorist.' Publishers Weekly