Not If, but When: Imagining a Nuclear 9/11

Graham Allison

As unpleasant and as frightening as it may be, the United States must come to grips with the prospect of facing a terrorist strike using nuclear materials--a "nuclear 9/11"--within the coming decade.

Nobody can predict with any certainty how--or when--such an attack will occur. This does not mean, however, that such an assault is therefore unlikely or improbable. 9/11 proved that the United States is not invulnerable to terrorist attack. Indeed, I have never understood those who believed that America could not or would not be targeted for attacks. After all, we do not reside on another planet, apart from the rest of the world. Moreover, we are an open society, with relatively porous borders. As I have been arguing for the past decade, we should anticipate the likelihood of major attacks on American soil, especially as groups like Al-Qaeda were moving, step by step, to assault larger and more complex targets.

Why am I convinced that an act of nuclear terrorism lies in our future? Sherlock Holmes had a simple methodology for solving crimes--motive, means and opportunity. I think that anyone who applies the same tools to this question will conclude that a nuclear 9/11 is a distinct possibility.

It is true that some terrorist groups, in the past, have refrained from acts of mass carnage, whether out of humanitarian or moral considerations, or because they judged such acts to be detrimental to their cause. As I see it, however, Al-Qaeda has no such inhibitions. Recently, Suleiman Abu Ghaith, a Kuwaiti-born cleric who functions as a spokesman for Al-Qaeda, a kind of terrorist Ari Fleischer, if you will, declared: "Al-Qaeda has the right to kill four million Americans, including one million children, displace double that figure, and injure and cripple hundreds of thousands." He believes that only by inflicting mass casualties on the United States can Al-Qaeda hope to even the balance sheet for what they consider to be the number of deaths caused by the West in the Muslim world. Such a desire to kill, maim, and injure millions provides motive for the acquisition of nuclear weapons--the only real way to kill on that scale.

It is one thing, of course, to fantasize about killing millions, but another thing altogether to actually be in a position to carry it out. But, I believe that Al-Qaeda and groups like it will try to construct or acquire a nuclear weapon. Given the right materials--and yes, as President Bush stated in last week's address to the nation, a grapefruit- or soccer ball-sized amount of fissionable material is sufficient--several masters-level nuclear engineering students from Ohio State with several hundred thousand dollars and the type of equipment you could purchase off the shelf at Radio Shack could make a device that would explode. The last time I checked, researchers at Los Alamos, trying to develop strategies to combat this threat, had come up with sixty-nine different workable designs for a nuclear device.

The plain and simple truth is that the construction of a nuclear weapon is no longer beyond the means of groups with sufficient funds, expertise and materials at their disposal.

If a group has a device, what is there to prevent them from detonating it, say in Washington, or New York, or Boston? There is no magical shield protecting our cities from attack. We have no clairvoyant means to anticipate and eliminate such threats. Certainly, the fact that it has not yet already happened indicates that we are doing some things right. We've also been lucky. But if a nuclear terrorist attack were to occur tomorrow, or next week, when we next met, the consensus would be that such an attack was to be expected--inevitable, over time.

To combat this threat, we must first be prepared to imagine the unimaginable--there is a substantial probability that within the next decade, an act of nuclear terrorism will occur. We can then move to strategies commensurate with a real war on nuclear terrorism aimed at minimizing this danger. The article that Andrei Kokoshin and I co-authored for the fall 2002 issue of The National Interest ("The New Containment", available at http://www.nationalinterest.org/issues/69/allisonkokoshin.html) sketches out such a strategy. The prime target in preventing nuclear terrorism is to prevent terrorists from acquiring a nuclear weapon or the fissile material (HEU or PU) from which a nuclear weapon could be made. Physics, fortunately, presents an inescapable fact: no fissile material, no nuclear explosion, no nuclear terrorism. While vast, the amount of fissile material is finite (and the challenge of producing more difficult). Technologies for locking up dangerous material are well developed. Thus a strategy that could prevent (or reduce to a very low probability) acts of nuclear terrorism is neither beyond our imagination or our reach--if we would stretch.

The question remains whether governments must wait until the morning after the first nuclear terrorist attack to act.

Graham Allison is director of the Belfer Center for Science and International Affairs at Harvard's John F. Kennedy School of Government. During the first Clinton Administration, he served as Assistant Secretary of Defense for Policy and Plans.