Continued from page 1

A country that knowingly and deliberately supplied the material might rate a military response; one that had massive stockpiles of uranium and plutonium, previously under loose controls, might get off more lightly if it could show it sought to recover missing material. There is no reason the United States or other potential victim countries need make public their contemplated reactions in advance, and every reason the potential victims should have well-thought-through contingency plans.

There is another benefit to a PIT. Providing samples to the PIT laboratory system could be written into safeguards agreements that cover states such as Iran that declare they wish to enrich or reprocess nuclear material purely for peaceful purposes.

We have focused on nuclear explosives because they present the greatest threat. But “dirty bombs” are likelier to be used. A broad program of nuclear forensics combined with an appropriate PIT library of samples will help track the perpetrators of a radiological attack.

We believe the risk of a nuclear strike by terrorists is real and think a good system to identify the culprit is the first, essential step toward reducing the prospects of such a catastrophe.

Peter D. Zimmerman, a nuclear physicist is professor of science and security in the War Studies Department of King’s College, London, and is the former chief scientist of the Senate Foreign Relations Committee. Hans Binnendijk is the Theodore Roosevelt Chair and founding director of the Center for Technology and National Security Policy at the National Defense University. The opinions expressed are the authors’ own and not necessarily those of the United States government or any organizations with which they are affiliated.