Dr Patricia Lewis is Research Director for International Security at Chatham House. Previously she served as Deputy Director and Scientist-in-Residence at the Center for Nonproliferation Studies at the former Monterey Institute of International Studies; Director of the UN Institute for Disarmament Research; and Director of the Verification Research, Training and Information Centre in London. She was on Hans Blix’s 2004–06 WMD Commission; the 2010–11 Advisory Panel on the future priorities of the Organisation for the Prohibition of Chemical Weapons; and was an adviser to the 2008–10 International Commission on Nuclear Non-proliferation and Disarmament. She received the American Physical Society’s 2009 Joseph A. Burton Forum Award for ‘outstanding contributions to the public understanding or resolution of issues involving the interface of physics and society’. She graduated in Physics from Manchester University and has a PhD in Nuclear Physics from Birmingham University.