We’ve now passed the tenth anniversary of the 9/11 attacks, and widely expected acts of nuclear terrorism have yet to occur. One example: Graham Allison predicted in Nuclear Terrorism (2004) that, “In my considered judgment, on the current path, a nuclear terrorist attack on America in the decade ahead is more likely than not.”
We all know that the most likely form of nuclear terrorism is the use of a “dirty” bomb. There is no shortage of material for these instruments of mass disruption, and much of it is not well secured. As for an improvised nuclear device, we know about successful intercepts of small quantities of fissile material, but not about successful transactions. If there is opportunity – and presumed motive – why hasn’t a dirty bomb attack – or far worse – already happened?


