In assessing Graham Allison’s roadmap (“The Will to Prevent: Global Challenges of Nuclear Proliferation,” Fall 2006) “to predict and prevent global (nuclear) catastrophe,” let’s first get down to basics. He tells us, “If terrorists acquired the 100 pounds of HEU (highly enriched uranium) needed for an elementary nuclear bomb, they could have a working bomb in less than a year.” It is curious that he does not mention plutonium here. Could it have been an oversight? Not likely.

In today’s hyperventilation to nip nuclear terrorism in the bud, the fl avor of the month is HEU. After decades of neglect, fl edgling efforts to repatriate bomb-grade uranium from vulnerable research reactor sites have suddenly won outspoken backing from nonproliferation heavyweights like Allison and former US Senator Sam Nunn, not to mention hundreds of millions of dollars in federal funding recently doled out, compared with the couple of million in years past.

But how about plutonium? Can’t terrorists make bombs with that, too? In 1987 the Nuclear Control Institute assembled a team of nuclear bomb designers (including the former head of weapons design at Los Alamos), to address whether terrorists could make nuclear weapons. The team concluded that they could do so with plutonium as well as with HEU.

In 1997 the US Department of Energy found that “at the lowest level of sophistication, a potential proliferating state or subnational group using designs and technologies no more sophisticated than those used in fi rst-generation nuclear weapons could build a nuclear weapon from reactorgrade plutonium that would have an assured, reliable yield of one or a few kilotons (and a probable yield signifi cantly higher than that).”

In the prescriptive, concluding section of his article, Allison does state, “As a fact of physics: no highly enriched uranium or plutonium, no nuclear bomb, no nuclear terrorism. It is that simple.” And he further warns that “highly enriched uranium and plutonium are bombs just about to hatch.” Doesn’t that settle the matter? No.

It is dangerously misleading to suggest, as Allison and Nunn often do, that HEU is the bomb material of choice for would-be nuclear terrorists. By not mentioning plutonium, they imply it is too diffi cult for terrorists to build implosion bombs, a necessity for plutonium, compared with gun-type devices, which are suitable for HEU but not plutonium. Bear in mind that A.Q. Khan has been peddling a tested Chinese design for an implosion bomb suitable for use with plutonium (or HEU). Copies are in the hands of Libyans, North Koreans, Iranians (almost certainly), not to mention Pakistanis. Given this provenance, might the design be in the hands of Al Qaeda and Chechnians, too?

It is reckless to suggest that HEU must be prohibited because of the terrorist threat but that plutonium can be managed because terrorists really couldn’t make a bomb with it. Plutonium management is what interests Harvard dons and former Senators because it involves international cooperation, introduces US and Russian weapons-grade plutonium into commercial nuclear power plants, establishes IAEA plutonium fuel-cycle centers, and seeks to negotiate with an Iranian jihadist regime a package of Atoms- for-Peace carrots that, to quote Allison, “Iran cannot reasonably refuse.”

If reason were all that were needed, proliferation would have been eliminated decades ago. What’s needed is bareknuckle gutterfighting that knocks out plutonium as well as HEU.