Marion Messmer

Marion is 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. Marion has also given evidence to parliament and is a member of several expert dialogues on space security and emerging technologies.

Marion writes extensively on European security and on the changing character of warfare and diplomacy, including the role of emerging technologies in reshaping strategic competition.

Before joining Chatham House, Marion was co-director of BASIC, where she led the organization’s nuclear risk reduction and disarmament work.

Marion is an N2 Innovation Fellow (2020–2021) and an ACONA Fellow (2021–2022). She holds a PhD in Security Studies from King’s College London, where her research focused on NATO–Russia relations.