Over the last thirty-five years, Western liberal democracies have exerted more control over their borders through an array of innovative migration-control practices. Scholars have taken stock of these efforts and referred to them collectively as “deterrence” measures, ignoring the fact that deterrence is an established concept with a focused definition and meaning. We argue that in the context of migration governance, the concept of deterrence has been stretched beyond meaningful parameters. In order to restore conceptual clarity and develop a more useful framework, we build on the fourth wave of deterrence literature and apply its insights to these new migration-control practices. We construct a theoretically informed typology that differentiates between deterrence and defense policies. Deterrence aims to change the motivations of migrants, whereas defense policies change migrants’ capabilities. We also differentiate between the timing and location of the interventions. We elaborate on each category of policy with examples drawn from various geographic regions and propose a framework for expanding this analysis through a systematic exploration of global practices. We conclude with a discussion of the implications stemming from these insights with respect to normative and practical debates in this research area.
