Marion Messmer
Programme Director at Chatham House
Marion Messmer is the Programme Director for International Security at Chatham House. She has expertise in arms control, nuclear weapons policy, and Russia–NATO relations, with a particular focus on nuclear risk reduction and NPT diplomacy. She has designed several intergovernmental processes in these areas and has served on government working groups on nuclear deterrence. M Messmer has also given evidence to parliament and is a member of several expert dialogues on space security and emerging technologies. She writes extensively on European security and on the changing character of warfare and diplomacy, including the role of emerging technologies in reshaping strategic competition.
Updated: August 12, 2026