Thèse de doctorat : Euro-British Foreign Intelligence Cooperation through Brexit and Russia’s Invasion of Ukraine: Trust and Network Power in Times of Crisis
9 janvier 2026
Le Secrétariat permanent du CRE adresse ses chaleureuses félicitations à la Dr Lucia Frigo pour l’aboutissement réussi de sa thèse de doctorat, soutenue en novembre 2025 à Royal Holloway, University of London. Ses recherches portent sur la question particulièrement actuelle et très pertinente de la coopération euro-britannique en matière de renseignement extérieur dans le contexte du Brexit et de l’invasion de l’Ukraine par la Russie, avec un accent particulier sur la confiance et le pouvoir des réseaux en temps de crise.
Veuillez trouver ci-dessous le résumé en anglais:
Euro-British foreign intelligence cooperation through Brexit and Russia’s invasion of Ukraine – trust and network power in times of crisis.
This work investigates how the United Kingdom (UK)’s relationship with the European Union’s framework for foreign intelligence sharing adapted in the decade between 2016 and 2025, through momentous changes such as Brexit and Russia’s war in Ukraine. The goal is to understand the extent and effects of these transformations on the EU intelligence network and on its ability to respond to external threats. To address this puzzle, two questions are asked: how have the relationships between British and EU polities, organisations, and practitioners adapted to these crises on a more granular level? And how well do the current intelligence-sharing channels satisfy the parties’ cooperative needs?
Dr Frigo adopts a socio-relational perspective to conduct a longitudinal network analysis of EU intelligence-sharing in three phases: pre-Brexit, post-Brexit, and after Russia’s invasion of Ukraine. By presenting the UK as a node in the EU’s deeply interconnected network, Dr. Frigo examines the UK’s changing power in the network, but also the ways in which the relations between London and the network’s hubs (such as IntCen, EUMS INT and SIAC) responded to the transformations. This highlights the key role of trust in intelligence cooperation and offers insightful explanations as to how the network adapted to changes through formal and informal cooperative avenues.
The interdisciplinary study, sitting at the crossroads of International Relations and Law, rests on novel empirical data gathered in 31 elite interviews with current and former intelligence practitioners, diplomats and experts from civil society (from the UK, the EU and its member states). The interview data is then triangulated with desk research conducted on publicly available data. The results challenge the widely held assumption that nothing would change with Brexit, since intelligence was never an EU competence and state-to-state relations would survive unscathed. Instead, this thesis highlights the changes in the UK’s network power, both with regards to the influence of its classified intelligence and to the circulation of its expertise and know-how. At the same time, and from a legal perspective, the study reveals the difficulties of ensuring adequate accountability and oversight when cooperation between the EU and the UK (now a third party) takes place through such informal avenues, and especially in times of crisis.
While bilateral relations and other, non-EU initiatives such as the Intelligence College in Europe (ICE) ensure that the UK remains central in its cultural role, the British influence in the network is also maintained through the lower-level relations, namely the inter-personal and interorganisational ties. These relationships, resting on a more reputational interpretation of trust, grant flexibility and resilience to the network. In practice, they ensured that the response to Russia’s invasion of Ukraine was concerted and collaborative even in the absence of an arrangement on EUUK foreign security cooperation. However, whilst these lower-level channels allowed timely cooperation in the short term, the thesis warns about the perils of overly relying on organisational and personal connections in the long term. Analysing the EU-UK Security and Defence Partnership of May 2025 and confronting it with the interviewees’ demands for the future of intelligence cooperation, Dr. Frigo finds that much remains to be done, at the inter-polity level, to offer stability in the long-term relationship.
The thesis’ contribution to the discipline is thus threefold. Empirically, it offers a precise and comprehensive explanation of how the UK’s role in the EU intelligence-sharing network adapted to recent developments, and of how these affected the network’s responses to external threats. Theoretically, this project offers insight on how intelligence alliances overcome crises, through an innovative approach that can delve into the specificities of micro- and macro- cooperative dynamics while subsuming them rigorously in a holistic network perspective. Its socio-relational approach challenges the still dominant neorealist school of intelligence cooperation, revealing the importance of factors such as trust in evolving intelligence alliances. Finally, and based on novel interview data, the thesis offers policy recommendations for the future of the relationship, contributing to inform future negotiations.
