Post-Brexit EU/UK Security Cooperation: NATO, CSDP+ or ‘French Connection’?

The aim of our paper is to investigate the impact of Brexit on EU’s foreign, security and defence policy. First, we identify political variables that determine the impact such as the extent to which the EU and UK will seek to align their capabilities and security arrangements, and thus which resources will still be counted as part of the common effort; the assessment of the institutional arrangements to be adopted and the extent of UK involvement in evolving EU defence mechanisms and decision-making arenas. In the next step, we examine how competing pressures on each side will play out over the next few years. To do so, we apply a question-driven approach that allows us to benefit from a greater plurality of existing scholarly approaches and to consider a greater variety of competing – and complementary – processes at work. We put forward four questions, each of which is the subject of a number of competing pressures, such that clear answers have been difficult to discern: (1) Will Brexit occasion significant effects in foreign affairs?, (2) Will the UK’s commitment to European defence and security diminish in the wake of Brexit?, (3) Will Brexit result in further integration in the fields of foreign, security and defence?, and (4) Will the EU seek, or allow, the UK a significant role in external action? These questions help us sort through some of the distinct elements in the complex and inter-connected Brexit process. We examine these four questions systematically, assessing the arguments that have been laid down on either side of the debate, and considering the most likely outcomes in the years ahead.