The United Kingdom’s (UK) approach towards the European Union (EU) after Brexit varies considerably across issue areas. In some policy domains, the UK is seeking cooperative rapprochement with the EU. In others, the UK is pushing for demarcation from the EU. And in yet other issue areas, the UK is manoeuvring back and forth between cooperation and contestation. What explains these varying post-withdrawal strategies? We argue that the UK after Brexit is an instance of the Disintegration Dilemma. We posit that after withdrawing from Regional International Organizations (RIOs), leaving states face both incentives to distance themselves from the organization through demarcation due to their decision to take back control, and incentives to continue cooperation through rapprochement due to strong interdependencies. While all states are confronted with these two opposing imperatives after exit, their strength varies across policy domains depending on two conditions: (1) the politicization of an issue during the exit, which drives benefits from retaining control; and (2) the issue-specific vulnerability from interdependency of the leaving state, which shapes its relative power vis-à-vis the RIO and thus drives the benefits from continued cooperation. The combination of these two conditions moderates the strength of the Disintegration Dilemma and shapes leaving states’ strategic choice between demarcation and rapprochement. To probe our argument in the case of Brexit, we employ a multi-method approach. An expert survey about the UK’s post-Brexit strategy across 17 issue areas and four in-depth case studies for migration, fisheries, finance, and justice and internal affairs corroborate our expectations. The Disintegration Dilemma promises to contribute to a better understanding of international politics in a highly interdependent world where RIOs face escalating contestation.
Benjamin Daßler & Tim Heinkelmann-Wild 2025: The Disintegration Dilemma: Politicization, Interdependence, and the UK’s Differentiated Strategy vis-à-vis the EU after Brexit. Working paper.