Two months after the 9/11 attacks, Usama bin Ladin claimed to possess a nuclear capability.[1] On the morning of November 8, 2001, the Saudi militant was eating a hearty meal of meat and olives as Hamid Mir, a Pakistani journalist, interviewed him in a house in Kabul. Mir asked Bin Ladin to comment on reports that he had tried to acquire nuclear and chemical weapons, to which the al-Qa`ida leader replied: “I wish to declare that if America used chemical or nuclear weapons against us, then we may retort with chemical and nuclear weapons. We have the weapons as deterrent.”[2] Mir asked, “Where did you get these weapons from?” Bin Ladin responded coyly, “Go to the next question.”[3] After the interview was finished, Mir followed up this exchange over tea with Bin Ladin’s deputy, Ayman al-Zawahiri. “I asked this question to Dr. al-Zawahiri: that it is difficult to believe that you have nuclear weapons,” Mir explained. “So he said, ‘Mr. Hamid Mir, it is not difficult. If you have 30 million dollars, you can go to the black market in Central Asia, make contact with a disgruntled Russian scientist and get from him suitcase nuclear weapons.’”[4]

Al-Qa`ida’s nuclear weapons claims came after a long quest by the terrorist organization to research nuclear technology and acquire nuclear materials. Sensing the inadequacy of his own knowledge about nuclear weapons, Abu Khabab al-Masri, the terrorist group’s in-house weapons of mass destruction researcher, asked his al-Qa`ida bosses in a pre-9/11 memo whether it was possible to get more information about nuclear weaponry “from our Pakistani friends who have great experience in this sphere.”[5] For that information, al-Qa`ida’s leaders turned to Dr. Sultan Bashiruddin Mahmood, a recently retired senior Pakistani nuclear scientist sympathetic to the Taliban.[6] Mahmood failed polygraph tests about his meetings with al-Qa`ida’s leaders once those encounters became known to U.S. and Pakistani investigators. Mahmood met with Bin Ladin over the course of two meetings just weeks before the 9/11 attacks, during which he provided information to the al-Qa`ida leader about the infrastructure needed for a nuclear weapons program.[7]

Bin Ladin’s and al-Zawahiri’s portrayal of al-Qa`ida’s nuclear and chemical weapons capabilities in their post-9/11 statements to Hamid Mir was not based in any reality, and it was instead meant to serve as psychological warfare against the West. There is no evidence that al-Qa`ida’s quest for nuclear weapons ever went beyond the talking stage. Moreover, al-Zawahiri’s comment about “missing” Russian nuclear suitcase bombs floating around for sale on the black market is a Hollywood construct that is greeted with great skepticism by nuclear proliferation experts. This article reviews al-Qa`ida’s WMD efforts, and then explains why it is unlikely the group will ever acquire a nuclear weapon.

Al-Qa`ida’s WMD Efforts

In 2002, former UN weapons inspector David Albright examined all the available evidence about al-Qa`ida’s nuclear weapons research program and concluded that it was virtually impossible for al-Qa`ida to have acquired any type of nuclear weapon.[8] U.S. government analysts reached the same conclusion in 2002.[9] There is evidence, however, that al-Qa`ida experimented with crude chemical weapons, explored the use of biological weapons such as botulinum, salmonella and anthrax, and also made multiple attempts to acquire radioactive materials suitable for a dirty bomb.[10]

After the group moved from Sudan to Afghanistan in 1996, al-Qa`ida members escalated their chemical and biological weapons program, innocuously code-naming it the “Yogurt Project,” but only earmarking a meager $2,000-4,000 for its budget.[11] An al-Qa`ida videotape from this period, for example, shows a small white dog tied up inside a glass cage as a milky gas slowly filters in. An Arabic-speaking man with an Egyptian accent says: “Start counting the time.” Nervous, the dog barks and then moans. After struggling and flailing for a few minutes, it succumbs to the poisonous gas and stops moving. This experiment almost certainly occurred at the Darunta training camp near the eastern Afghan city of Jalalabad, conducted by the Egyptian Abu Khabab.[12]

Not only has al-Qa`ida’s research into WMD been strictly an amateur affair, but plots to use these types of weapons have been ineffective. One example is the 2003 “ricin” case in the United Kingdom. It was widely advertised as a serious WMD plot, yet the subsequent investigation showed otherwise. The case appeared in the months before the U.S.-led invasion of Iraq, when media in the United States and the United Kingdom were awash in stories about a group of men arrested in London who possessed highly toxic ricin to be used in future terrorist attacks. Two years later, however, at the trial of the men accused of the ricin plot, a government scientist testified that the men never had ricin in their possession, a charge that had been first triggered by a false positive on a test. The men were cleared of the poison conspiracy except for an Algerian named Kamal Bourgass, who was convicted of conspiring to commit a public nuisance by using poisons or explosives.[13] It is still not clear whether al-Qa`ida had any connection to the plot.[14]

In fact, the only post-9/11 cases where al-Qa`ida or any of its affiliates actually used a type of WMD was in Iraq, where al-Qa`ida’s Iraqi affiliate, al-Qa`ida in Iraq (AQI), laced more than a dozen of its bombs with the chemical chlorine in 2007. Those attacks sickened hundreds of Iraqis, but the victims who died in these assaults did so largely from the blast of the bombs, not because of inhaling chlorine. AQI stopped using chlorine in its bombs in Iraq in mid-2007, partly because the insurgents never understood how to make the chlorine attacks especially deadly and also because the Central Intelligence Agency and U.S. military hunted down the bomb makers responsible for the campaign, while simultaneously clamping down on the availability of chlorine.[15]

Indeed, a survey of the 172 individuals indicted or convicted in Islamist terrorism cases in the United States since 9/11 compiled by the Maxwell School at Syracuse University and the New America Foundation found that none of the cases involved the use of WMD of any kind. In the one case where a radiological plot was initially alleged—that of the Hispanic-American al-Qa`ida recruit Jose Padilla—that allegation was dropped when the case went to trial.[16]

Unlikely Al-Qa`ida Will Acquire a Nuclear Weapon

Despite the difficulties associated with terrorist groups acquiring or deploying WMD and al-Qa`ida’s poor record in the matter, there was a great deal of hysterical discussion about this issue after 9/11. Clouding the discussion was the semantic problem of the ominous term “weapons of mass destruction,” which is really a misnomer as it suggests that chemical, biological, and nuclear devices are all equally lethal. In fact, there is only one realistic weapon of mass destruction that can kill tens or hundreds of thousands of people in a single attack: a nuclear bomb.[17]

The congressionally authorized Commission on the Prevention of Weapons of Mass Destruction Proliferation and Terrorism issued a report in 2008 that typified the muddled thinking about WMD when it concluded: “It is more likely than not that a weapon of mass destruction will be used in a terrorist attack somewhere in the world by the end of 2013.”[18] The report’s conclusion that WMD terrorism was likely to happen somewhere in the world in the next five years was simultaneously true but also somewhat trivial because terrorist groups and cults have already engaged in crude chemical and biological weapons attacks.[19] Yet the prospects of al-Qa`ida or indeed any other group having access to a true WMD—a nuclear device—is near zero for the foreseeable future.

If any organization should have developed a serious WMD capability it was the bizarre Japanese terrorist cult Aum Shinrikyo, which not only recruited 300 scientists—including chemists and molecular biologists—but also had hundreds of millions of dollars at its disposal.[20] Aum embarked on a large-scale WMD research program in the early 1990s because members of the cult believed that Armageddon was fast-approaching and that they would need powerful weapons to survive. Aum acolytes experimented with anthrax and botulinum toxin and even hoped to mine uranium in Australia. Aum researchers also hacked into classified networks to find information about nuclear facilities in Russia, South Korea and Taiwan.[21]

Sensing an opportunity following the collapse of the Soviet Union, Aum recruited thousands of followers in Russia and sent multiple delegations to meet with leading Russian politicians and scientists in the early 1990s. The cult even tried to recruit staff from inside the Kurchatov Institute, a leading nuclear research center in Moscow. One of Aum’s leaders, Hayakawa Kiyohide, made eight trips to Russia in 1994, and in his diary he made a notation that Aum was willing to pay up to $15 million for a nuclear device.[22] Despite its open checkbook, Aum was never able to acquire nuclear material or technology from Russia even in the chaotic circumstances following the implosion of the communist regime.[23]

In the end, Aum abandoned its investigations of nuclear and biological weapons after finding them too difficult to acquire and settled instead on a chemical weapons operation, which climaxed in the group releasing sarin gas in the Tokyo subway in 1995. It is hard to imagine an environment better suited to killing large numbers of people than the Tokyo subway, yet only a dozen died in the attack.[24] Although Aum’s WMD program was much further advanced than anything al-Qa`ida developed, even they could not acquire a true WMD.

It is also worth recalling that Iran, which has had an aggressive and well-funded nuclear program for almost two decades, is still some way from developing a functioning nuclear bomb. Terrorist groups simply do not have the resources of states. Even with access to nuclear technology, it is next to impossible for terrorist groups to acquire sufficient amounts of highly enriched uranium (HEU) to make a nuclear bomb. The total of all the known thefts of HEU around the world tracked by the International Atomic Energy Agency between 1993 and 2006 was just less than eight kilograms, well short of the 25 kilograms needed for the simplest bomb;[25] moreover, none of the HEU thieves during this period were linked to al-Qa`ida.

Therefore, even building, let alone detonating, the simple, gun-type nuclear device of the kind that was dropped on Hiroshima during World War II would be extraordinarily difficult for a terrorist group because of the problem of accumulating sufficient quantities of HEU. Building a radiological device, or “dirty bomb,” is far more plausible for a terrorist group because acquiring radioactive materials suitable for such a weapon is not as difficult, while the construction of such a device is orders of magnitude less complex than building a nuclear bomb. Detonating a radiological device, however, would likely result in a relatively small number of casualties and should not be considered a true WMD.

There is also the concern that a state may covertly provide a nuclear device to a terrorist group. This was one of the underlying rationales to topple Saddam Hussein’s government in Iraq in 2003. Yet governments are not willing to give their “crown jewels” to organizations that they do not control, and giving a terrorist group a nuclear weapon would expose the state sponsor to large-scale retaliation.[26] The United States destroyed Saddam’s regime on the mere suspicion that he might have an active nuclear weapons program and that he might give some kind of WMD capacity to terrorists. Also, nuclear states are well-aware that their nuclear devices leave distinctive signatures after they are detonated, which means that even in the unlikely event that a government gave a nuclear weapon to terrorists, their role in the plot would likely be discovered.[27]

Just as states will not give nuclear weapons to terrorists, they are unlikely to sell them either. This leaves the option of stealing one, but nuclear-armed states, including Pakistan, are quite careful about the security measures they place around the most strategic components of their arsenals. After 9/11, the United States gave Pakistan approximately $100 million in aid to help secure its nuclear weapons.[28] The U.S. Department of Defense has assessed that “Islamabad’s nuclear weapons are probably stored in component form,”[29] meaning that the weapons are stored unassembled with the fissile core separated from the non-nuclear explosive.[30] Such disassembling is just one layer of protection against potential theft by jihadists.[31] A further layer of protection is Permissive Action Links (PAL), essentially electronic locks and keys designed to prevent unauthorized access to nuclear weapons; Pakistan asserts that it has the “functional equivalent” of these.[32] As a result of these measures, Michael Maples, the head of the U.S. Defense Intelligence Agency at the time, told the Senate Armed Services Committee in March 2009 that “Pakistan has taken important steps to safeguard its nuclear weapons.”[33]

What has distinguished al-Qa`ida from other terrorist groups is that its leaders have made it clear publicly that they would deploy such weapons without hesitation, despite the fact that privately some al-Qa`ida leaders were aware that their WMD program was strictly an amateur affair.[34] This was the mirror image of the Cold War, where the Soviets had enough nuclear devices to end civilization, yet their intentions about what they might do with those weapons were so opaque that the art of Kremlinology was created to divine what their plans might be. The Soviets had the capability to destroy the United States but never really had the intention to do so, while al-Qa`ida’s leaders have said they intend to kill millions of Americans but their ability to do so has been nonexistent.


Nevertheless, governments must be cognizant that scientists motivated either by greed or ideology might give WMD technology to terrorist groups. Yet even a group armed with such scientific knowledge would still have to overcome enormous technical challenges to build a workable nuclear device or to weaponize agents such as anthrax. As a result, groups such as al-Qa`ida will, for the foreseeable future, continue to use the tried-and-true tactics of hijackings, truck bombs, and suicide attacks, rather than being able to successfully execute the quite complex and prohibitively expensive task of developing true WMD. This, of course, does not preclude al-Qa`ida or its affiliates from deploying crude biological, chemical, or radiological weapons during the coming years, but these will not be “weapons of mass destruction.” Instead, they will be weapons of mass disruption, whose principal effect will be panic and a limited number of casualties.

Peter Bergen is a fellow at the New America Foundation and New York University’s Center on Law and Security.

[1] This marked Usama bin Ladin’s first public statement claiming to have a nuclear capability.

[2] Hamid Mir, “Osama Claims he has Nukes: If US Uses N-Arms it Will Get Same Response,” Dawn, November 10, 2001.

[3] Ibid.

[4] Personal interview, Hamid Mir, Islamabad, Pakistan, May 11, 2002.

[5] Roland Jacquard, L’Archive Secretès d’al Qaida (Paris: Jean Picollec, 2002), p. 291.

[6] Graham Allison, Nuclear Terrorism: The Ultimate Preventable Catastrophe (New York: Henry Holt, 2004), pp. 20-22.

[7] Peter Baker, “Pakistani Scientist Who Met Bin Laden Failed Polygraphs, Renewing Suspicions,” Washington Post, March 3, 2002.

[8] David Albright, Kathryn Buehler, and Holly Higgins, “Bin Laden and the Bomb,” Bulletin of the Atomic Scientists 58:1 (2002).

[9] Thom Shanker, “U.S. Analysts Find No Sign Bin Laden Had Nuclear Arms,” New York Times, February 26, 2002.

[10] Barton Gellman, “Al Qaeda Nears Biological, Chemical Arms Production,” Washington Post, March 23, 2003.

[11] Anne Stenersen, Al-Qaida’s Quest for Weapons of Mass Destruction: The History Behind the Hype (Saarbrücken, Germany: VDM Verlag, 2009), p. 35.

[12] Nic Robertson, “Tapes Shed New Light on Bin Laden’s Network,” CNN, August 19, 2002.

[13] Stenersen, p. 48; Walter Pincus, “London Ricin Finding Called a False Positive,” Washington Post, April 14, 2005. For details on Bourgass, see Duncan Campbell, “Yesterday’s Trial Collapse has Exposed the Deception Behind Attempts to Link al-Qaida to a ‘Poison Attack’ on London,” Guardian, April 14, 2005.

[14] Vikram Dodd, “Doubts Grow Over al-Qaida Link in Ricin Plot,” Guardian, April 16, 2005.

[15] Stenersen, p. 42; “‘Chlorine Bomb’ Hits Iraq Village,” BBC, May 16, 2007; Personal interview, Charles Faddis, Central Intelligence Agency officer involved in the effort against Iraq’s chlorine bomb makers in 2007, Washington, D.C., January 20, 2010.

[16] Peter Bergen and Bruce Hoffman, “Assessing the Terrorist Threat,” A Report of the Bipartisan Policy Center’s National Security Preparedness Group, September 10, 2010.

[17] Creating true WMD using chemical and biological weapons is complex because “weaponizing” such devices is quite difficult. Consider that the anthrax attacks in the United States in the fall of 2001 which targeted a number of politicians and journalists caused considerable panic but only killed five people. The Federal Bureau of Investigation concluded that Bruce E. Ivins was the author of that attack. Before he committed suicide, Ivins was one of the leading biological weapons researchers in the United States. Even this skilled scientist only weaponized anthrax to the point that it killed a handful of people, albeit it is not clear whether his intent was to infect a large number of people or strictly target certain individuals.

[18] Bob Graham et al., World at Risk: The Report of the Commission on the Prevention of Weapons of Mass Destruction Proliferation and Terrorism (New York: Vintage Books, 2008).

[19] In 1984, for instance, in The Dalles, Oregon, followers of the Indian guru Bhagwan Shree Rajneesh tried to swing a local election by infecting salad bars throughout the town with salmonella. Hundreds succumbed to severe food poisoning, but no one died in the biological attack.

[20] Sara Daly, John Parachini and William Rosenau, Aum Shinrikyo, Al Qaeda, and the Kinshasa Reactor (Santa Monica, CA: RAND Corporation, 2005).

[21] Ibid.

[22] Ibid.

[23] Ibid.

[24] David Kaplan and Andrew Marshall, The Cult at the End of the World: The Terrifying Story of the Aum Doomsday Cult, from the Subways of Tokyo to the Nuclear Arsenals of Russia (New York: Crown, 1996), pp. 33, 65, 157-167.

[25] “Combating Illicit Trafficking in Nuclear and Other Radioactive Material,” IAEA Nuclear Security Series No. 6, 2007, pp. 129-130.

[26] Brian Michael Jenkins, Will Terrorists Go Nuclear? (Amherst, NY: Prometheus Books, 2008), p. 143.

[27] Daniel Chivers and Jonathan Snider, “International Nuclear Forensics Regime,” Security for a New Century Study Group Report, February 2, 2007.

[28] Thom Shanker and David Sanger, “Pakistan is Rapidly Adding Nuclear Arms, U.S. Says,” New York Times, May 17, 2009.

[29] “Proliferation: Threat and Response,” U.S. Department of Defense, January 2001, p. 27.

[30] “Nuclear Weapons Status 2005,” Carnegie Endowment for International Peace, available at

[31] Paul Kerr and Mary Beth Nikitin, “Pakistan’s Nuclear Weapons: Proliferation and Security Issues,” Congressional Research Service, June 12, 2009.

[31] Ibid.; Peter Crail, “Pakistan Nuclear Stocks Safe, Officials Say,” Arms Control Today, June 2009.

[32] Michael Maples, “The Current and Future Worldwide Threats to the National Security of the United States,” U.S. Senate Armed Services Committee, March 10, 2009. One caveat: Shaun Gregory of the University of Bradford in The Terrorist Threat to Pakistan’s Nuclear Weapons in the CTC Sentinel of July 2009 pointed out that while these weapons are unassembled, “Pakistan’s usual separation of nuclear weapons components is compromised to a degree by the need to assemble weapons at certain points in the manufacture and refurbishment cycle at civilian sites, and by the requirement for co-location of the separate components at military sites so that they can be mated quickly if necessary in crises.”

[33] Abu Walid al-Masri, The History of the Arab Afghans from the Time of their Arrival in Afghanistan until their Departure with the Taliban, serialized in al-Sharq al-Awsat, December 8-14, 2004.

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