One of the costs of Brexit is the weakened ability of both the UK and the EU to shape a strong joint response to Russia’s threats to pan-European security. In the standoff over Ukraine, the need for close cross-Channel cooperation is particularly acute for any effective sanctions package negotiated with the US. Yet, post-Brexit relations between the UK and the EU are currently governed by a narrow Trade and Cooperation Agreement (TCA) which does not include a designated chapter on political dialogue and that, barring a handful of exceptions, does not contain any provisions on cooperation on foreign and security matters. Fortunately, the preparatory work undertaken to reach the bilateral accord contains the answer to the question on how trust between the parties can be regained through procedural means. This policy brief highlights the embers of the Brexit bonfire that might be raked up to rekindle the flame of dialogue and cooperation between the UK and the EU in foreign affairs and security policy.