Thinking out of the accession box: the potential and limitations of internal and external differentiated integration between Turkey and the EU

The multiple crises the European Union (EU) has been facing - such as the rather “traditional” sovereign debt crisis, and the “new generation” crises including the Brexit, the rise of terror attacks within the EU borders and the refugee crisis – have led to increased focus on the possibilities to accomplishing extended internal differentiated integration within the EU. Internal differentiated integration in the EU could be defined as an arrangement among the Member States with regards to the formulation of a polity, which “displays variance across policy areas and across space, while maintaining an institutional core” .The aim is to “reconcile heterogeneity within the European Union.” In other words, differentiated integration encapsulates “the multiple forms of European integration” as it reflects the particularities of a system that allows for “a variety of forms of cooperation and/or integration in which not all members of the EU take part.