Over the past several years, the prospect of a terrorist group armed with a nuclear weapon has frequently been cited as a genuine and overriding threat to the security of the United States. Moreover, press reports indicate that the forthcoming Nuclear posture review will make the goal of countering nuclear terrorism “equal to the traditional mission of deterring a strike by major powers or emerging nuclear adversaries.”1 Although the likelihood of a nuclear terrorist attack may be relatively low, the consequences of such an attack would obviously be enormous. There is, therefore, widespread agreement regarding the severity of this threat. Despite this consensus, a number of important questions remain open to debate: How real is the risk that a terrorist group could acquire or construct a functional nuclear device, and how might it attempt to do so? Which group poses the greatest threat in this regard, how has that threat changed over time, and is it currently growing or abating? What existing and prospective measures will prove most effective in preventing terrorists from obtaining a nuclear weapon, stopping them from delivering and detonating a weapon if prevention fails, and responding both at home and abroad in the event that an attack succeeds? The purpose of this backgrounder is to examine these critical issues.
Sources of the Nuclear Terrorist Threat
There are two major dimensions of the nuclear terrorist threat: the “supply” side of nuclear proliferation and the “demand” side of violent Islamist extremism. Over the past decade, longstanding concerns over proliferation have become increasingly acute in light of a number of worrisome developments, including the status of India and Pakistan as overt nuclear weapon states, North Korea’s two nuclear weapons tests, the international community’s failure to restrain Iran’s nuclear ambitions, and the fear that an Iranian nuclear weapons program could spark further proliferation throughout the Middle East. Ultimately, while existing nuclear arsenals and stockpiles of fissile material represent the most immediate concern, the spread of nuclear weapons and material has increased the probability that terrorists might be able to acquire or construct a nuclear device. At the same time that nuclear proliferation has become a growing concern, terrorism has also been elevated from a secondary to a primary threat to US security because of the emergence of groups that have few inhibitions on inflicting mass casualties by means of chemical, biological, and even nuclear weapons. Today, for example, the threat of nuclear terrorism is primarily associated with Osama bin Laden and his followers, who have not only pursued these weapons for some time, but have expressed their willingness to use them against their enemies.
Since the US invasion of Afghanistan in 2001, however, al Qaeda has lost a key sanctuary and much of its original senior leadership. Does it still hope to acquire and use weapons of mass destruction? is it capable of obtaining or building a nuclear weapon? The answer to the first question appears to be “yes.” Publicly available information leaves little doubt that the group’s intentions remain unchanged. Nevertheless, al Qaeda appears to be much less capable of conducting a major attack against the United States, and especially a catastrophic attack using a nuclear weapon, than it was when it had a base of operations in Afghanistan. After the downfall of the Taliban regime, al Qaeda evolved into an increasingly decentralized organization. Moreover, as the influence and capabilities of its central leadership have waned, the source of the terrorist threat has shifted toward regional groups affiliated with al Qaeda and homegrown extremists inspired by it, neither of which are likely to possess the knowledge, skills, resources, or discipline necessary to plan and successfully carry out a nuclear attack.
Until fairly recently, however, numerous accounts suggested that al Qaeda’s core leadership was in the process of reestablishing its ability to organize and execute major attacks, due in large part to its sanctuary in the remote areas of Pakistan. Yet according the United States intelligence Community this concern has diminished over the past year due to ongoing counterterrorism efforts, including repeated strikes against terrorist operatives using unmanned aerial vehicles operating in Pakistan. These efforts “have put the organization into one of its most difficult positions since the early days of Operation Enduring Freedom in late 2001,” and have also “dealt a significant blow to al-Qa’ida’s near-term efforts to develop a sophisticated CBRN [chemical, biological, radiological, or nuclear] attack capability.”
An analysis of the supply and demand sides of the nuclear terrorist threat suggests two major conclusions. First, limiting and preferably stopping any further proliferation of nuclear weapons and the technology to produce nuclear material is and will remain an important goal. At present, this goal hinges largely on Iran — if Tehran does pursue and develop nuclear weapons, this could be the catalyst for a wave of proliferation in the Middle East. As one analyst notes, “The real danger is that Iran’s nuclearization would help create a region in which four or five nations are nuclear-armed, instead of just one (Israel).” Yet stopping Iran from becoming a nuclear weapon state, while certainly desirable, may not be feasible through diplomacy, economic sanctions, or even military action. The United States must, therefore, work to develop a comprehensive strategy to prevent further proliferation in the region if and when Iran does become a full-fledged nuclear power. Second, because there is a very strong probability that any credible plot to conduct a nuclear terrorist attack will originate with al Qaeda’s central leadership, a critical component of a broader strategy to prevent such an attack will involve continued efforts to weaken al Qaeda’s leaders and eliminate — or at the very least restrict — their sanctuary in Pakistan.