The law as tool and constraint of differentiated integration

Abstract

In recent years, leading political actors and institutions have suggested further differentiation as a plausible scenario for the EU's future, in fields such as economic governance, social Europe, migration, tax harmonisation, and defence. One central question is to what extent such scenarios require revision of the current EU Treaties and which ones can, on the contrary, be implemented under the current Treaty text. As the chances for Treaty revision are very remote, the latter option is the more promising. This paper explores the main legal mechanisms allowing for further differentiation, namely enhanced cooperation and the conclusion of separate international agreements between a group of EU states. It examines their legal feasibility and the legal constraints that affect their potential use.