Book excerpt: This book examines the management of migratory flows in the Mediterranean within an international security perspective. The intense migratory flows registered during the year 2015 and the tragedies in the Mediterranean Sea have tested the mechanisms of the Union’s immigration and asylum policies and its ability to respond to humanitarian crises. Moreover, these flows of varying intensities and geographies represent a threat to the internal security of the EU and its member states. By using Spain and Italy as case studies, the author theorizes that the EU, given its inability to adopt and implement a common policy to effectively manage migratory flows on its Southern border, uses a deterrence strategy based on minimum common denominators.