The authoritative timeline.
In 1998, al Qaeda leader Osama bin Laden declared that acquiring and using weapons of mass destruction (WMD) was his Islamic duty -- an integral part of his jihad. Systemically, over the course of decades, he dispatched his top lieutenants to attempt to purchase or develop nuclear and biochemical WMD. He has never given up the goal; indeed, in a 2007 video, he repeated his promise to use massive weapons to upend the global status quo, destroy the capitalist hegemony, and help create an Islamic caliphate.
Since the mid-1990s, al Qaeda's WMD procurement efforts have been managed at the most senior levels, under rules of strict compartmentalization from lower levels of the organization, and with central control over possible targets and the timing of prospective attacks. The modus operandi has been top-down -- more similar to the 9/11 attacks than to more recent bottom-up efforts, like the attempted bombing of Flight 253. For instance, al Qaeda deputy chief Ayman al-Zawahiri personally shepherded the group's ultimately unsuccessful efforts to set off an anthrax attack in the United States.
Al Qaeda concentrated its efforts on nuclear devices in the run-up to the September 11, 2001 attacks. Based on the timing and nature of its WMD-related activity in the 1990s, al Qaeda hoped to use such weapons in the United States during an intensified campaign following the 9/11 attacks. There is no indication that the fundamental objectives that lie behind its WMD intent have changed over time.
Al Qaeda seems to have failed in its mission to successfully detonate WMD due to its overpowering interest in such big-casualty, big-impression attacks. The organization has not pursued simpler, cheaper, and easier-to-use technologies, like crude toxins and poisons, with anything like the same fervor. To be sure, experimentation with and training in such agents was standard fare in al Qaeda's camps in Afghanistan before 9/11. But bin Laden and his top associates left the initiative to lower-ranking planners and individual cells. Once, Zawahiri even canceled a planned attack on the New York City subway in lieu of "something better" that never materialized.
But just because "something better" has never materialized, and just because the threat of WMD terrorism has been used to political ends, does not mean that WMD are not a threat. This chronology provides the knowable extent of al Qaeda's interest in, plans to obtain, and efforts to use the world's most deadly weapons.
Winter 1990 - Spring 1991: Bin Laden and his associates relocate to Khartoum, Sudan.
Feb. 26, 1993: A car bomb is detonated under the World Trade Center in New York City. According to Federal Judge Kevin Duffy, the goal of al Qaeda mastermind Ramzi Youssef was to "engulf the victims trapped in the North Trade Tower in a cloud of cyanide gas." The explosion incinerates the gas, greatly decreasing the number of casualties. Five people die.
Late 1993 - early 1994: Al Qaeda tries to acquire uranium in Sudan to use in a nuclear device. This is the first evidence of bin Laden's plans to purchase nuclear material for an improvised nuclear device.
Evidence of this attempted transaction comes from Fadl, who defected from al Qaeda in 1996 and became a source for the FBI and CIA. He testifies in court that former Sudanese President Saleh Mobruk attempted to help al Qaeda acquire uranium of South African origin. Fadl says he heard later that the uranium, which al Qaeda acquired for $1.5 million and was tested in Cyprus, was "genuine."
1996: Zawahiri, leader of the Egyptian Islamic Jihad (which later merged into al Qaeda), is detained and released by the state security service in Russia. There is unconfirmed speculation that Zawahiri was seeking nuclear weapons or material there.
May 21, 1996: Abu Ubeida al-Banshiri, a founder of al Qaeda, dies in a ferry accident on Lake Victoria. According to testimony from senior al Qaeda officials, he was seeking nuclear material in southern Africa.
May 1996: Al Qaeda's leadership relocates to Afghanistan.
Early 1998: Zawahiri's Egyptian Islamic Jihad (EIJ) merges with al Qaeda. Zawahiri and EIJ bring technological know-how about chemical, biological, radiological, and nuclear weapons to the more ideological al Qaeda. Zawahiri takes control of nuclear and biological weapons development for the whole organization.
Before this time, high-ranking al Qaeda members had held internal discussions about the wisdom and efficacy of pursuing chemical, biological, radiological, and nuclear interests. 1998 marked the year when systematic and programmatic efforts began.
Feb. 23, 1998: Bin Laden issues a fatwa against the United States, saying, "The ruling to kill the Americans and their allies -- civilians and military -- is an individual duty for every Muslim who can do it in any country in which it is possible to do it."
Aug. 7, 1998: Al Qaeda initiates simultaneous suicide truck-bomb attacks at the U.S. embassies in Dar-es-Salaam, Tanzania, and Nairobi, Kenya. At least 230 civilians, mostly locals, die. The FBI places bin Laden on its "10 most wanted" list and starts monitoring al Qaeda closely.
Aug. 20, 1998: The United States destroys the Al-Shifa pharmaceutical factory in Khartoum, Sudan, based on suspicions that the plant might be producing the nerve agent VX for the Sudanese government and al Qaeda.
Dec. 24, 1998: Osama bin Laden states in an interview with Time's Rahimullah Yusufzai: "Acquiring [WMD] for the defense of Muslims is a religious duty."
1999-2001: Al Qaeda training camps in Afghanistan conduct basic training courses in chemical, biological, and radiological weapons for hundreds of extremists. Abu Khabab al-Masri, a chemist and top bomb-maker, and Abu Musab al-Suri (better known as Setmariam), a Spanish citizen born in Syria, conduct the training courses at the Durante and Tarnak farms.
Setmariam is captured in a raid in Pakistan on Nov. 3, 2005. The outspoken proponent of using chemical, biological, radiological, and nuclear weapons in attacks against the United States tells authorities that al Qaeda had made a mistake by not utilizing WMD on Sept. 11, 2001.
Early 1999: Zawahiri recruits a midlevel Pakistani government biologist with extremist sympathies, Rauf Ahmed, to develop a biological weapons program. He is provided with a laboratory in Kandahar, Afghanistan.
Early 1999: The head of Jemaah Islamiyah (JI), an al Qaeda-associated militant Islamist group based in southwest Asia, introduces an ex-Malaysian Army captain and California Polytechnic State University (better known as CalPoly) graduate, Yazid Sufaat, to Zawahiri.
Zawahiri starts a second, independent, parallel program to the al Qaeda Afghanistan program, with Sufaat at the helm. Neither program knows of the existence of the other; each reports to Zawahiri independently. This collaboration between al Qaeda and JI is likely the first instance of Islamist terrorist groups jointly developing WMD.
The Afghanistan program, headed by Ahmed, acquires equipment and sets up labs. Sufaat, a more trusted JI member, focuses on developing the anthrax pathogen. He has been described as the "CEO" of al Qaeda's anthrax program.
1999-2001: Al Qaeda's Abdel Aziz al-Masri conducts nuclear-related explosive experiments in the desert. He is an explosives expert and chemical engineer by training, reportedly self-taught on things nuclear.
January 2001: Pakistani nuclear scientists with extremist sympathies create the humanitarian nongovernmental organization Umma Tameer e Nau (UTN). Bashiruddin Mahmood, the former head of Pakistan's Khushab plutonium reactor, is its chair; the former head of Pakistan's Inter-services Intelligence directorate, Hamid Gul, is on its board.
Mahmood is later forced into retirement due to concerns about his extremist sympathies and reliability. He pens controversial books predicting an imminent apocalypse, offering a radical interpretation of the Quran.
June 2001: Sufaat hosts a meeting of the 9/11 attackers in Kuala Lumpur. Sufaat provides a false Malaysian address for Zacarias Moussaoui, who was arrested shortly before 9/11, to help him travel to the United States.
Before Aug. 2001: UTN's Mahmood discreetly offers to construct chemical, biological, or nuclear weapons programs for al Qaeda and the Libyan government. The United States gathers intelligence on the offers and passes it to the Libyan intelligence service office in London. The head of the London office later confirms to the United States that Libya will have no dealings with UTN.
August 2001: Zawahiri personally inspects Ahmed's completed laboratory in Kandahar. He separately meets with Sufaat for a weeklong briefing on the reportedly successful efforts to isolate and produce a lethal strain of anthrax.
Summer 2001: Mohammed Atta, an organizer and leader of the Sept. 11 attacks, allegedly meets with WMD figures, including al Qaeda's Adnan Shukrijumah. According to the FBI, Shukrijumah cases targets in New York City for possible attacks; he is later associated with multiple nuclear and "dirty bomb" plots.
A person fitting Atta's description seeks to apply for a loan to purchase a crop duster in Florida, and is refused. After 9/11, the FBI approaches every U.S. crop duster company, searching for links to terrorists.
Summer 2001: The United States detains Abderraouf Yousef Jdey, who traveled with Moussaoui from Canada into the United States. Moussaoui is detained with crop duster manuals in his possession; Jdey has biology textbooks. They might have been involved in planning a second wave of attacks for immediately after 9/11.
Sept. 11, 2001: Nineteen members of al Qaeda board two passenger planes in the United States, hijacking them and piloting them into the two towers of the World Trade Center in New York. Nearly 3,000 die.
September 2001: Al Qaeda breaks camp. Most senior operatives and their families flee Afghanistan in anticipation of an imminent U.S. invasion.
Oct. 7, 2001: The United States launches Operation Enduring Freedom, invading Afghanistan to neutralize and destroy al Qaeda and bin Laden.
Oct. 23, 2001: Pakistani intelligence services detain a long list of UTN members and associates, at the request of the U.S. government.
Sometime this month, George Tenet, the director of the CIA, meets with President Pervez Musharraf of Pakistan regarding the threat posed by UTN and the evidence that al Qaeda might be building chemical, biological, and nuclear weapons programs. Musharraf reportedly responds, "Men in caves can't do that."
Still, Musharraf agrees to work with the U.S. government to out and arrest Pakistani scientists cooperating with al Qaeda. Musharraf and Pakistan's intelligence services follow through with the promise.
1990s-2001: A nuclear weapons network run by the father of the Pakistan nuclear weapons program, Abdul Qadeer Khan, supplies Iran, North Korea, and Libya with nuclear technologies and know-how. Nuclear bomb designs are found on the computer of a European supplier working with the Khan network. Al Qaeda reportedly contacts associates of Khan for assistance with their weapons program. The Khan network rejects them, for unknown reasons.
Nov. 7, 2001: Bin Laden states in an interview with Pakistani journalist Hamid Mir, "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 a deterrent."
In the same interview, Zawahiri states, "If you have $30 million, go to the black market in central Asia, contact any disgruntled Soviet scientist, and a lot of dozens of smart briefcase bombs are available. They have contacted us, we sent our people to Moscow to Tashkent to other central Asian states, and they negotiated and we purchased some suitcase bombs."
Nov. 14, 2001: U.S. President George W. Bush meets with Russian President Vladimir Putin in Crawford, Texas. Bush presents a briefing on the proliferation threat posed by UTN. Bush asks Putin if he is certain that all Russian nuclear weapons and materials are secure. Putin responds that he can only vouch for the safety of nuclear materials since he gained power.
November 2001: Pakistan arrests Mahmood and many other members of UTN. Mahmood confesses that he met with bin Laden around a campfire that summer in Pakistan. He says they discussed how al Qaeda could build a nuclear device. He drew a very rough sketch of an improvised nuclear device, but advised bin Laden that it would be too hard to develop weapons-usable materials for it. Bin Laden reportedly said, "What if I already have them?"
November 2001: A search of UTN's Kabul office produces documents containing crude chemical, biological, radiological, and nuclear-related plans, including hand-written notes in Arabic and Internet-related searches.
December 2001: Malaysian authorities arrest Sufaat, the JI leader working with al Qaeda on nuclear weapons. Pakistani authorities arrest Ahmed, his Afghan counterpart, at his home in Islamabad. Ahmed confesses his involvement in the project and provides substantiating evidence.
January 2002: U.S. and Egyptian forces capture al Qaeda senior operative Ibn al-Shaykh al Libi. During interrogation by Egyptians, al Libi claims al Qaeda operatives received chemical, biological, radiological, and nuclear weapons training in Baghdad. He claims several small containers of nuclear material were smuggled into New York City by the Russian mafia. Al Libi later recants this statement.
March 2002: Russian special services assassinate Chechen leader Ibn al-Khattab, using poison, the kind of weapon he hoped to use against high-level Russian targets.
March 28, 2002: U.S. and Pakistani forces capture al Qaeda leader Abu Zubaydah in Faisalabad, Pakistan. During interrogation, he reveals a plot by an American associate of al Qaeda, Jose Padilla, to explode a "dirty bomb" in the United States. Padilla is subsequently identified and arrested in Chicago.
Spring 2002: In Khartoum, Sudan, a CIA officer meets with two senior al Qaeda associates, Mubarak al-Duri and Abu Rida Mohammed Bayazid, in a brokered arrangement. The CIA officer attempts to determine whether they were involved in al Qaeda's nuclear and biological weapons programs.
Bayazid, a founding member of al Qaeda, graduated from the University of Arizona with an advanced degree in physics. He was directly involved in al Qaeda's attempt to purchase uranium in 1993 and 1994. Al-Duri, an agronomist, also received his degree at the University of Arizona. He told the CIA officer, "Killing millions [of you] is justifiable by any means.... It is your doing. You made us what we are."
Summer 2002: Al Qaeda leaders in Saudi Arabia begin planning attacks against the royal family and Saudi oil assets. Nuclear and biological weapons-related references begin to appear in communications between top-level al Qaeda leaders and the Saudi cell.
Summer 2002: With bin Laden's blessing, al Qaeda issues two fatwas to justify an escalation of terrorism. One authorizes attacks on infidels other than Americans, including the Saudi royal family. The other justifies the use of WMD. Al Qaeda-associated extremists start to case Saudi targets, including the city of Ras al-Tanura and facilities belonging to oil giant Aramco.
June 2002: Extremists under Zarqawi's command conduct crude chemical and biological training and experiments in a remote camp, Khurmal, in northeastern Iraq. The commanders include men who served with Zarqawi at the Herat camp. Zarqawi has close ties with al Qaeda, but is an independent operator who never swore loyalty (bayat) to bin Laden.
July 10, 2002: Al Qaeda spokesman Sulayman Abu Ghayth al-Libi, under "house arrest" in Iran, says al Qaeda's fatwa justifies the use of WMD to kill four million Americans.
August 2002: CNN runs an exposé on al Qaeda's late-1990s experiments with crude toxins and poisons. Abu Khabab al-Masri led the gruesome efforts, testing the lethality of cyanide creams, ricin, mustard, sarin, and botulinum. A tape shows al Qaeda associates gassing dogs to death. Al-Masri later laments that his students did not take the training to heart by using the toxic weapons in terrorist attacks.
September - December 2002: Zarqawi associates infiltrate Turkey, Britain, Spain, Italy, France, Sweden, Germany, and other countries. They begin coordinating and planning ricin and cyanide attacks via a loose association of cells.
Bush and Vice President Dick Cheney receive briefings on the Zarqawi network's activities and plans to attack with poisons and toxins. Over the course of several briefings, U.S. knowledge of the extent of the network grows from a handful of terrorists in one country to dozens of extremists in 30 countries.
Jan. 5, 2003: In a bloody raid on a safehouse, Britain arrests seven extremists plotting to use ricin poison on the London Underground. This represents the first in a wave of arrests of Zarqawi-network terrorists in Britain, continental Europe, and beyond. The arrests confirm intelligence reports, producing forensic evidence of planning for crude-poison and toxin attacks.
January - March 2003: Zarqawi-associated operatives are arrested, disrupting ricin and cyanide attacks, in Britain, Spain, Italy, and France.
Feb. 5, 2003: U.S. Secretary of State Colin Powell gives a speech to the U.N. Security Council, naming the Herat camp leadership, including Zarqawi. He identifies poison-attack cells across Europe.
February - March 2003: Zarqawi returns to Baghdad to prepare for an insurgency to meet the U.S. invasion of Iraq.
March 1, 2003: 9/11 mastermind Khalid Sheikh Mohammed (KSM) is captured in Pakistan. Confronted with the evidence found during the raid, KSM confirms some details of al Qaeda's nuclear and biological weapons programs. He later recants some of his testimony.
March 2003: Zawahiri calls off an attack that had been planned against the New York City subway system, in lieu of "something better." Al Qaeda associates from Bahrain had cased the subway system in December 2002 and planned an attack with a homemade cyanogen gas-releasing device called a "mobtaker."
March-May 2003: Al Qaeda Saudi senior operative Abu Bakr communicates with Iran-based al Qaeda senior members, including the chief of operations. They plan to purchase three "Russian nuclear devices." An unidentified Pakistan specialist is enlisted to verify the goods.
May 21, 2003: Radical Saudi cleric Nasir al-Fahd writes a fatwa justifying the use of WMD. Another radical cleric, Ali al-Khudair, endorses it.
May 28, 2003: The Saudi intelligence agency makes a series of arrests in a campaign to neutralize al Qaeda in Saudi Arabia and eliminate its capacity to mount attacks. Al-Fahd is arrested. Cyanide is found in an al Qaeda safehouse in Riyadh.
June 26, 2003: An Armenian citizen, Garik Dadayan, is caught with 170 grams of highly enriched uranium on the Georgia-Armenia border. This is allegedly a sample of a larger cache, due to be sold to an unknown customer, possibly in the Middle East.
Aug. 13, 2003: Riduan Isamuddin, the head of JI, is arrested. He provides confirmation of his role in the anthrax program.
After August 2003, it is not possible to extend the chronology without excluding considerable information that is sensitive or classified. Even though the passage of time has enabled more of the story of al Qaeda's WMD efforts to be told, much detail remains too sensitive to reveal, even in the years covered by this chronology. It is not the author's intent to reveal information that might frustrate efforts to identify and neutralize al Qaeda's ongoing efforts to develop weapons of mass destruction. Rather, it is his hope that an accurate portrayal of a compact period in the recent past would enable the reader to develop an understanding of the intensity of al Qaeda's interest in WMD, as well as an appreciation for the U.S. government's response to it.