Internal differentiation and external unity

Abstract

To what extent is differentiated integration compatible with the presentation of the European Union as a single actor on the world stage, a single legal personality with the capacity to enter into international obligations? How does differentiated integration impact EU foreign policy, positively or negatively, at the level of decision-making, and what kinds of legal issues arise where not all Member States may be bound by external action undertaken by the EU? This contribution raises a number of questions about the way in which the EU operates externally and the links between internal differentiation and external unity, taking as a central example the opt-out from the Area of Freedom, Security and Justice currently applied to Denmark, the UK and Ireland.