Sebastian Brixey-Williams


Sebastian Brixey-Williams is the Co-Director of BASIC, alongside Marion Messmer, where he works to build international trust, reduce nuclear risks and advance multilateral disarmament.

Sebastian’s practice centres around trust and confidence-building between ​nuclear possessor and ​n​on -possessor ​s​tates, applying principles drawn from mediation, conflict resolution and conflict transformation to nuclear diplomacy in order to break through existing deadlocks. Since 2016, Sebastian has been the Director of the Programme on Nuclear Responsibilities: a multi-year diplomatic initiative which serves to foreground states’ conceptions of their responsibilities around nuclear weapons and the global norms by which they abide.

Sebastian is also interested in finding new ways to engage and educate the general public on nuclear weapons issues, through multi-stakeholder collaborations with the media, private sector and artists. Sebastian regularly appears in the national and international media for comment on international security and nuclear weapons policy issues. He has published in Arms Control Wonk, The Bulletin of the Atomic Scientists, the European Leadership Network, and the World Economic Forum, and his work has recently featured on BBC News, BBC Radio 4, CGTN, The Economist, Forces TV, The Guardian, and Sky News. He has addressed three All-Party Parliamentary Groups – on Drones, on Global Security and Non-Proliferation, and on Future Generations – and has been called to give evidence to the House of Lords International Relations Committee.

Sebastian is a member of the Younger Generation Leadership Network and the co-founder of the Gender, Think Tanks and International Affairs breakfast series with Chatham House and the Centre for Feminist Foreign Policy. He holds a first-class degree from the University of York in English and Related Literature, and a first-class Master’s in International Studies and Diplomacy from the School of Oriental and African Studies (SOAS), where he received the Postgraduate School’s Prize.


  • Multilateral nuclear disarmament, arms control and risk reduction
  • Global norms and responsibilities around nuclear weapons
  • Emerging technologies, especially naval drones and sensing
  • The Treaty on the Prohibition of Nuclear Weapons (Nuclear Ban Treaty)
  • The United Kingdom’s nuclear weapons diplomacy
  • The Trident Programme

Contact Sebastian

Office: +44 20 3488 6974

Read Sebastian Brixey-Williams’ Content

Discover below Sebastian’s posts ordered from newest to oldest

Report: Nuclear Responsibilities – A New Approach for Thinking and Talking about Nuclear Weapons

We seek in this report to suggest ways, and crucially propose a new method, to gradually shift the nature of the contemporary global conversation on nuclear weapons away from one characterised by rights, blame, and suspicion towards one framed by responsibility, empathic cooperation, and even trust.  

Houses of Parliament

Parliamentary Briefing: House of Lords Debate on ‘Rising nuclear risk, disarmament and the Nuclear Non-Proliferation Treaty’

This parliamentary briefing was issued in advance of the Debate on the report from the International Relations Committee ‘Rising nuclear risk, disarmament and the Nuclear Non-Proliferation Treaty’, Tuesday, 16th of July 2019. This is an opportunity to consider the ways in which the UK can reduce nuclear risks globally, and engage in meaningful multilateral disarmament processes ahead of the 2020 Non-Proliferation Treaty Review Conference.

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