EU Common Foreign and Security Policy after Brexit: A Security and Defence Treaty for the ‘Deep and Special Partnership’

Abstract

The United Kingdom has indicated its willingness to maintain, after Brexit, a ‘deep and special partnership’ with the EU in the field of security and defence. The Draft Withdrawal Agreement leaves open the opportunity for the EU and the UK to conclude a Treaty on Common Foreign and Security Policy (CFSP), which may be applicable during the transition period. Despite not having figured prominently in the referendum campaign, the issue raises questions of constitutional importance for the EU. This article proposes four possible scenarios for how the ‘deep and special partnership’ of the UK and EU may look like from a legal perspective – in particular, what will be the future participation of the UK in the EU’s Common Foreign and Security Policy. This arrangement is hereby discussed under the name of Security and Defence Treaty. While the intricacies of the legal disentanglement only offer a partial view of the full impact of Brexit, the UK’s withdrawal might considerably and negatively affect the European Union’s influence in security and defence.

Keywords: Brexit, CFSP, EU