When politics trumps strategy: UK–EU security collaboration after Brexit

Monika Sus and Benjamin Martill explore how political dynamics can undermine strategic cooperation. 

In a blog post featured by the Brexit Institute, Monika Sus, Fellow at Hertie School’s Centre for International Security, and Benjamin Martill, Lecturer at the University of Edinburgh, discuss the omission of security and defense measures from the recently enacted EU-UK Trade and Cooperation Agreement (TCA). Their research, published in the International Political Science Review, contends that failure to cooperate on these issues was due to the politics of the exit process itself.  

Given the shared strategic interests of the UK and EU regarding foreign, security, and defense policies, the exclusion of related provisions in the TCA has puzzled observers. Sus and Martill argue that the heightened distrust and hardened preferences unleashed by the withdrawal process eclipsed the mutual strategic incentive to cooperate or coordinate on external and security policy. In this way, the dynamics of moving away from existing forms of cooperation are highly distinct from the factors motiving cooperation in normal times. 

According to Sus and Martill, “Time will tell whether the political will to negotiate an agreement will be found, or whether both sides will continue to diverge on their strategic worldview. Whatever happens in the future, it is clear that the political dynamics unleashed by withdrawal are just as important as underlying strategic considerations in determining the prospects for UK-EU security collaboration.” 

Access to the blog post can be found here. Access to the research publication can be found here.

  • Monika Sus, Visiting Professor, Centre for International Security