Differentiated Integration of Core State Powers at the EU’s External Borders

This article examines differentiated policy implementation in EU border management. Despite controversy and disagreements, EU policy-makers have been developing and offering a policy package to the frontier Member States in the areas of migration management and border controls, which involves direct engagement of EU agencies, such as the European Border and Coast Guard and the European Union Agency for Asylum. These agencies and national administrations are expected to collaborate closely to correctly implement EU laws and regulations. However, differentiation arises when some Member States accept the joint implementation approach, and others do not. The article suggests that opting out of the “agency solution” does not necessarily lead to permanent differentiation but rather to alternative methods of opting in. While differentiated implementation can be resilient and path-dependent, there has been convergence in border controls and crisis response.