By Pier Domenico Tortola

Differentiated integration (DI) is, in a way, both an old and a new topic for those interested in the European Union. It is an old topic because a certain degree of differentiation in membership has accompanied the European project for decades now, among others in such high profile projects as the Monetary Union, the Schengen space and the more recent Fiscal Compact. Yet, compared to those past experiences – or at least most of them – DI today is approached in a novel way, in academic as well as political debates. Previous instances of DI have been mostly seen as a “glitch” in the integration process, so to speak – a second best solution to be accepted when the optimal outcome, i.e., integration tout court, was not available. As a result the DI concept itself has long remained rather marginal in scholarly discussions on European integration. 1

Over the past decade or so, conversely, DI has become a much more prominent subject within European integration: one which, above all, is increasingly presented as a deliberate politico-institutional strategy to tackle the Union’s problems. The reasons for this are both structural – the EU’s large membership and therefore political diversity – and related to the multi-faceted crisis that has recently hit the Union. The main consequence is the opening of a new analytical space on the topic of DI, not only for better understanding the dynamics of differentiation, but also for reflecting more prescriptively on courses to follow, in order to ensure that future differentiation is both legitimate and efficient. It is exactly in this space that the EU IDEA project is located.

Much of what makes the subject of DI important today also makes it particularly challenging to devise viable strategies for differentiation. We still live in a juncture of great political fluidity and uncertainty, in which interests and alignments shift quickly and the economic conditions of many Member States remain precarious. In this context, constraints and opportunities for DI are a moving target. Two years ago the Istituto Affari Internazionali produced a series of studies on DI which, taken together, may be viewed as a pilot project for EU IDEA. The project’s introductory paper identified five distinct dimensions, presented as questions, along which to devise a strategy for differentiation: 1) DI for whom, and for what? 2) Temporal or permanent DI? 3) What legal instruments to use for differentiation? 4) How to make DI governable and effective? 5) How to make it legitimate? Responding to these questions, the paper argued that a viable strategy of differentiation should: 1) build on the “institutional anchors” of the Eurozone, Schengen and the more recent Permanent and Structured Cooperation in the area of defence; 2) strive for maximum openness but be prepared to last; 3) proceed as much as possible within the confines of the Treaties; 4) contain institutional duplication; and 5) safeguard input, output and throughput legitimacy with institutional and political means.2

By and large, these indications seem still applicable today. Compared to then, however, a number of aspects and problems should be added, to reflect both intervening political developments and the wider analytical latitude of EU IDEA. Three such aspects seem particularly important and therefore to be highlighted in the remainder of this article.

The first is Brexit. Three years after the referendum, the outcome of the Brexit saga is, if possible, even less clear than it was at its beginning – having most recently become intertwined with a new battle for the Tory leadership. When it comes to DI there are roughly three main questions raised by Brexit. The first has to do with the eventual form that the UK’s withdrawal from the Union will take, and in particular whether the “no deal” scenario will eventually materialise, or conversely the agreement negotiated by the May government (or some variation thereof) will eventually be implemented, thereby introducing a transitory DI regime which will pose a number of interesting questions as to its management and implications. The second question regards the post-withdrawal, long-term relationship between the UK and the EU which – to the extent that predictions are at all possible here – seems most realistically destined for some form of external cooperation. Finally, one should reflect on what Brexit will entail for (differentiated) integration among both remaining and prospective EU members, beginning with the simple question of whether Britain’s departure will make DI in the Union more or less likely in the future.

The second issue to be integrated in a reflection on DI is that of populism and Euroscepticism. As the dust of the recent electoral campaigns for the European Parliament settles, we should consider that while populists are still a minority in European institutions, they remain a force to be reckoned with in European politics more broadly defined. The task here is to integrate the rich debate and scholarly work on populism into the study of differentiation not only analytically, i.e., to examine causal relationships between the two, but also normatively, by engaging with some of the social grievances that populist parties often represent. Questions here include: What sort of relationship do different variants of populism (e.g., Northern vs. Southern, from new vs. old Member States, etc.) have with the notion and politics of DI? To what extent should we accept the de jure or de facto selective disengagement from EU arrangements and principles pursued by some Eurosceptic governments (put differently, where do we draw the line between differentiation and the need to preserve a community of values)? Finally, how does DI affect the legitimacy of the Union that is so often at the centre of populist Eurosceptic arguments?

The third and final aspect to be included in our analysis of DI has to do with the role that sub-state (and particularly regional and local) actors can play in differentiation. It is a paradox for a post-national project like the EU that the topic of differentiation is still studied and debated in almost completely state-centric terms. Transnational policy experiments and governance networks among sub-state actors – which in a way are, by definition, instances of differentiation – should be included in a broader discussion on DI. This would allow us not only to gauge to what extent these networks can themselves provide legitimate and efficient forms of integration and cooperation, but also to analyse their relationship with “traditional” DI, whether as facilitating (or hindering) factors, or perhaps as flexible channels to expand cooperation arrangements to local actors that are located outside the perimeter of state-driven integration.

Encompassing all these angles will place EU IDEA in a very good position to be a well rounded and successful research project: one able to tackle competently the analytical challenges posed by the complex topic of DI and to provide sensible and actionable suggestions for policy-making in this key area.

¹ A notable exception to this is the theoretical work of Frank Schimmelfennig and coauthors. See e.g. Dirk Leuffen, Berthold
Rittberger, and Frank Schimmelfennig, Differentiated Integration: Explaining Variation in the European Union, Basingstoke, Palgrave
Macmillan, 2012; Katharina Holzinger and Frank Schimmelfennig, “Differentiated Integration in the European Union: Many
Concepts, Sparse Theory, Few Data”, in Journal of European Public Policy, Vol. 19, No. 2 (2012), p. 292-305.
² Nicoletta Pirozzi, Pier Domenico Tortola, and Lorenzo Vai, “Differentiated Integration: A Way Forward for Europe”, Istituto Affari
Internazionali, March 2017.