From the core to the periphery of EU foreign policy : Brexit as a case of internal re-bordering of the EU

The paper investigates the effects of the UK’s decision to leave the European Union (EU) on cooperation dynamics among the remaining member states. To do so, it draws on critical border studies and the scholarship on voluntary withdrawals from International Organizations (IOs). The study conceptualises coalition-building and cooperation dynamics as inclusionary/exclusionary bordering practices, which help draw social boundaries between an intangible core and periphery within an IO. Focusing on EU foreign and security policy, I explore how the UK’s departure (re)shaped cooperation dynamics among the remaining members (internal re-bordering of the EU) and how, in turn, it pushed the UK away from the core to the periphery of the EU’s foreign policy cooperation networks. I examine how member states’ cooperation ties within the Political and Security Committee (PSC) – a pivotal EU preparatory committee of the Foreign Affairs Council – changed before and after the Brexit referendum. Descriptive social network analysis is complemented with qualitative evidence from two EU foreign policy negotiations, the 2014 debate on the Russian sanctions and the 2017 negotiations on Permanent Structured Cooperation. As the paper shows, Brexit did not fundamentally alter the structure of EU foreign policy cooperation networks. However, London’s influence over EU foreign policy had been diminishing well before the referendum and the UK’s loss of relative weight continued as it negotiated its exit agreement. At the same time, other member states have since stepped up to fill the UK’s shoes, either by performing similar roles (e.g. moderating differences between France and Germany) or advocating similar positions. The paper shows that while the structure of an IO might be resilient to the peripheralization of a (soon-to-be former) member state, internal bordering practices among the remaining countries do change as a result.