All in this Together? Communities of Practice in UK–EU Cybersecurity Relations Post‐Brexit and Differentiated Re‐engagement

Abstract Whilst formative work on characterising UK‐EU cybersecurity cooperation points to re‐engagement rather than disengagement, we seek to take this as our starting point in order to build a more complex picture on how Brexit has impacted practitioners at policy and operational levels. The article argues that while UK‐EU collaboration in cybersecurity has historically been robust, the politics of withdrawal/ Brexit have had varying effects on engagement at the level of the everyday: (1) business as usual in the domain of national security and information sharing; (2) re‐engagement in the law enforcement realm; and (3) a formal partial disengagement in the policy and institutional realm. We therefore highlight in this article a more nuanced and differentiated impact relating to Brexit and cybersecurity cooepration and show how established communities of practice have been able to uilise mechanisms of resistance to achieve their goals in a time of political turbulence.