The Four Faces of Nuclear Terror And the Need for a Prioritized Response

Graham Allison was among the first scholars to sound the alarm about the risks of Russian loose nukes, and in "How to Stop Nuclear Terrorism" (January/February 2004), he continues to warn of this underappreciated danger. He is right to highlight the inadequacy of current U.S. and international efforts to deny terrorists access to fissile material. And he makes a compelling case for the need to develop a more coherent and multilateral strategy for stopping them.

Unfortunately, Allison's article is less successful in describing the full scope of the problem and recommending a nuanced response. In particular, it fails to distinguish among four distinct types of nuclear terrorism, the relative risks posed by the main two types of fissile materials used in nuclear weapons, and the means necessary for keeping such weapons from nonstate actors as well as states.

OUT OF STATE

Allison addresses what is arguably the most urgent aspect of the threat of nuclear terror: the danger that terrorists will acquire the fissile materials needed to make nuclear bombs. His article, however, conveys the misleading impression that nuclear terrorism is a unitary phenomenon. In fact, terrorists present at least four different kinds of nuclear threats: that they will disperse highly radioactive material by conventional explosives (i.e., "dirty bombs") or other means, that they will attack or sabotage nuclear power installations, that they will seize intact nuclear weapons, and that they will steal or buy fissile material for the purpose of building a nuclear bomb. All four threats are real and merit the attention of policymakers. All four will be expensive to prevent or protect against. They all vary widely, however, in the probability that they will actually occur, in their potential for causing harm, and in the ease with which they can be prevented.

A fundamental shortcoming of the current U.S. policy to combat nuclear terrorism is that it fails to take these differences into account. As a result, Washington has no guidelines for directing its limited resources to where they would have the greatest impact. And Allison's proposed strategy of "three no's" (no loose nukes, no new "nascent nukes," and no new nuclear weapons states) does not help in this regard.

To begin with, his analysis of the dangers posed by "nascent nukes" (that is, fissile material that can be used to build nuclear bombs) does not take into account how this threat has changed since September 11, 2001. Before that date, many influential defense experts and weapons scientists assumed that because nuclear weapons had to meet rigorous military specifications (such as having predictable yields, being compatible with delivery systems, and satisfying safety and reliability standards), they were too difficult for terrorists to build without help from a sympathetic government.

It is now clear, however, that terrorists such as al Qaeda are not so exacting, and might be willing to settle for a crude "improvised nuclear device" (IND) that could be assembled at a target site. Policymakers should thus rethink the nonproliferation checks now in place. Washington and Moscow, however, have barely begun to do so. In fact, the top Russian atomic energy official continues to deny the very possibility that nonstate actors could have the skills necessary to manufacture a nuclear bomb, and some senior U.S. government officials agree.

Allison also fails to make a crucial distinction between highly enriched uranium (HEU), which terrorists may already have the capability to turn into the simplest IND (a gun-type device), and plutonium, which is much more difficult to turn into a weapon. Prior to September 11, when states presented the main proliferation challenge, it made sense to treat HEU and plutonium as roughly equivalent dangers. Today, however, when nonstate actors constitute a far greater nuclear threat, priority must be given to rapidly securing, consolidating, and eliminating the vast global stocks of HEU.

IS RUSSIA READY?

Allison's failure to articulate the need for an HEU-first consolidation and elimination strategy leads him to make an unrealistic proposal: that the United States and Russia lead a "Global Cleanout Campaign" to "extract all nascent nukes from all other countries" in 12 months. The problem with his proposal, which focuses on plutonium as well as HEU, is that it is hard to imagine that all of the world's other non-nuclear-weapons states -- much less those that already have such weapons -- will agree to it. A more feasible approach would be to pursue a three-pronged strategy that gives priority to securing, consolidating, and eliminating nonmilitary stocks of HEU within Russia; emphasizes the rapid repatriation of all Russian-origin HEU currently abroad; and undertakes a global campaign led by the United States, Russia, and other exponents of peaceful nuclear research to convert all research reactors to run on low-enriched uranium, which cannot fuel a nuclear bomb. These measures could be facilitated by providing financial incentives to accelerate the down-blending of HEU to an enrichment level unsuitable for nuclear weapons, and by securing several hundred tons of Russian HEU within the newly opened Mayak Fissile Material Storage Facility, currently reserved for plutonium storage.