In the past year, there has been notable progress in ensuring that stockpiles of the essential ingredients of nuclear weapons around the world are secured from theft and transfer to terrorists. But there remains a dangerous gap between the pace of progress and the scope and urgency of the threat – a gap that, if left unfilled, could lead to unparalleled catastrophe. We must close the gap – to take action now that, within a few years, could reduce the danger that terrorists might turn the heart of a U.S. city into a new Hiroshima to a fraction of what it is today. This paper is intended to outline the continuing threat; summarize the progress made in addressing it in the past year, and the gaps that still remain; and recommend steps to close the gap between threat and response. The terrorists who have sworn to kill Americans wherever they can be found have undertaken an intensive effort to get a nuclear bomb, or the materials and expertise needed to make one. We need to be racing as fast as we can to stop them before they succeed. This paper is about steps to win that race.
Bunn, Matthew. "Preventing Nuclear Terrorism: A Progress Update." Project on Managing the Atom, Harvard University and Nuclear Threat Initiative, 2003.