From Borders to Boundary Rules: Governing the EU Commons

The European Union (EU) began as a club, with strong borders and loose governance arrangements. Today, however, the borders of the EU are more permeable, the patterns of involvement more varied, and the membership more diverse. Governance arrangements are also more demanding: authority is more centralized, requirements for self-discipline more stringent and multilateral surveillance more necessary. The EU is no longer a club, but an arrangement for managing common resource pools (Anghel and Jones 2024). This arrangement also changes how the EU sets borders. Governing the EU commons demands the establishment of more complex boundary rules. Creating boundary rules around the EU commons is different from deciding who is in and who stays out. It means assigning rights, roles, and responsibilities that also extend to actors far beyond the geographic scope of the EU. Formal enlargement to countries that the EU already has dense cooperation with is more about strengthening that cooperation than redrawing frontiers. Formal enlargement contributes to gaining back some of the control the EU foregoes through arrangements of ‘external differentiated integration’ when outsiders only extract from the attractive goods that the EU generates and do not participate in the cost of maintaining these goods. This article contributes to the wider debate on EU scholarship on ‘deepening’ vs. ‘widening’ by challenging the idea that ‘enlargement’ is a ‘before and after’ event. While the meaning of ‘deepening’ has received various interpretations (Borzel et al. 2017), ‘widening’ has rarely been considered beyond the definition of adding new members. Our research shows that the porous nature of the EU asks for a more comprehensive understanding of what ‘enlargement’ means, with important implications for how we define the EU’s boundary rules (Ostrom 2005). In this model, the activity of non-member non-state actors within the EU commons is analysed to illustrate the extent to which the EU is challenged to set boundary rules even when it decides to establish geographical or political borders.