Visa policies have far-reaching impacts on areas such as international trade, tourism, migration, and security; but what are the determinants of visa policies? How do states decide whether they should open their borders to specific countries while imposing visa restrictions on others? Scholars have identified common history, cultural-religious affinity, shared language, and ideological similarity as some of the background conditions that favor open borders. Nazli Avdan’s recent book, Visas and Walls: Border Security in the Age of Terrorism, examines economic and security incentives that affect visa policies, paying particular attention to the role of transnational terrorist events.

Previous research has shown that deepening globalization leads to economic interdependence, inducing states toward more open border policies. However, Avdan argues that globalization is not limited to the economic realm. It carries security externalities when nonstate actors benefit from communication technologies and facilitate transnational criminal activities. As a result, Avdan states, “The security incentives of globalization … point to the opposite expectation: harder borders” (p. 16). However, what happens when economic interests and security objectives require different policy responses? Focusing on transnational terrorist threats, Avdan argu