From the Black Sea to the British Isles: Cooperation in Contested Waters

BY BUĞRA SÜSLER, JON-WYATT MATLACK, OLIVER GILL

The active hostilities between Ukraine and Russia exacerbate a pre-existing weakness in the region: the lack of a unified political forum for Black Sea littoral states.

This report summarises a high-level policy discussion convened by LSE IDEAS in partnership with the Foreign, Commonwealth & Development Office and the Embassy of Ukraine to the United Kingdom, held on 10 November 2025 at Lancaster House. Against the backdrop of the protracted war following Russia’s full-scale invasion of Ukraine, the discussion focused on the evolving security, trade, and political dynamics of the Black Sea region and explored policy instruments to support Ukraine and strengthen regional stability.

Drawing on off-the-record exchanges conducted under the Chatham House Rule, the report distils key insights from policymakers, industry representatives, and analysts from across the United Kingdom, Ukraine, and Black Sea littoral states. Central themes include the importance of safeguarding Ukraine’s sovereignty and maritime resilience, the lessons of the conflict for international partners, and the need to develop a durable framework for deterrence and cooperation in the region. Particular attention is given to the underexamined maritime domain and its role in shaping both wartime dynamics and long-term regional security.

Durable deterrence in the Black Sea depends not just on Ukraine’s battlefield resilience, but also on a security and connectivity order that raises the expected costs of future escalation and aggression."

This paper is published  as part of the Democratic Resilience in the New Age of War programme.

Meet the Authors

Buğra Süsler leads the Turkey and the World programme at LSE IDEAS. He is also Associate Professor of International Relations and Deputy Director of the Global Governance Institute at University College London (UCL). His research focuses on foreign policy and emerging powers.

Jon-Wyatt "Jack" Matlack is Project Associate for the Democratic Resilience in a New Age of War at LSE IDEAS Programme. Previously, Jack was a visiting fellow at IDEAS, the Centre for Military History of the German Armed Forces, and the University of Regensburg, where he submitted his PhD. His research focuses on NATO maritime strategy, multinational alliances, adaptive governance in Ukraine, and unmanned systems training in the armed forces.

Oliver Gill is Ukraine Programme Manager and Principal Researcher for the Democratic Resilience in a New Age of War Programme at LSE IDEAS. After completing a master’s in international relations at King’s College London with a focus on information warfare and AI, his research now focuses on Black Sea security, Ukrainian defence innovation, information and influence operations, training in the armed forces, and emerging and disruptive technologies’ impact on defence and security. Oliver also operates the Education for Victory capacity building programme, bringing together senior civil servants, business and third sector workers, and military personnel to address the challenges of reconstruction and recovery.