Conclusion: UK bilateralisms, dependencies and interdependencies in the post-Brexit era

This paper draws together the findings of the case studies of the EU, the UK and the 14 country case studies and reflects on the insights generated by the triangle metaphor, as well as its limitations and grey areas, e.g. how to situate the family of security and defence relations. The chapter highlights the key role of the EU, which constrains how member states as well as close affiliates such as Norway and Switzerland interact with third countries in general and with the UK in particular, and shows how, contrary to alternative conceptualisations that assume considerable agency on the part of the UK and freedom on the part of other European states, that the UK's bilaterals and bilateralism are in fact conditioned by the EU. However, reflecting the cross-sectoral variation in both EU competencies and the terms of EU-UK treaties, the paper shows how the structure of opportunity facing the UK and its partners differs between policy areas, which largely explains why the UK's bilateral interactions are strongest and most wide-ranging in defence and security. The paper also discusses the diversity of bilateral relations between the UK and its neighbours pre- and post-Brexit, considers the impact of the UK's departure on the substance of these relations and how they are conducted, and examines how the interaction between the three sides of the triangle varies cross-nationally. The paper concludes with reflections on avenues for future research.