The complete extent of Pakistani scientist Abdul Qadeer Khan’s decades-long involvement in the illegal transfer of nuclear materials and technologies is not known. The details are submerged in Khan’s work over the past thirty years, which has included both the development of Pakistan’s uranium enrichment capabilities and a complex international network of experts, suppliers, and front companies that have aided Iran, Libya, North Korea, and potentially others. Since we do not know exactly what Khan did, we cannot know when he did it. As more information is released from those who have questioned Khan and his network partners, a more complete image of the nuclear black market will emerge. This chronology summarizes what we now know.

Khan Builds His Base in Pakistan

Pre-1985: Khan’s early exposure to European technology and supply chains allow him to establish and develop uranium enrichment technologies in Pakistan. Knowledge of the technologies, and more importantly, the companies from which to obtain the necessary components set the foundation for how the future proliferation network would operate.

• Khan is born in Bhopal, which is part of British India. Khan will immigrate with his family to Pakistan in 1952, several years after India and Pakistan are partitioned.

• Khan moves to Europe to complete his studies, first in West Berlin and later at the Technical University in Delft, Holland, where he receives a degree in metallurgical engineering in 1967.

• Khan receives Ph.D. in metallurgical engineering from the Catholic University of Leuven in Belgium.
• May – Khan begins work at Physical Dynamic Research Laboratory (FDO), a subcontractor of Ultra Centrifuge Nederland (UCN). UCN is the Dutch partner in the Urenco uranium enrichment consortium.
• 8 May - Within one week of starting work at FDO, Khan visits the advanced UCN enrichment facility in Almelo, Netherlands to become familiar with Urenco centrifuge operations and the aspects relevant to his own work to strengthen the metal centrifuge components. Khan is not officially cleared to visit the facility, but does so many times with the consent of his employers.

Early 1970s
• Dutch intelligence begins to monitor Khan soon after he begins work at FDO, concerned by a series of inquiries about technical information not related to Khan’s own projects.

• 18 May – India conducts its first nuclear test, a “peaceful nuclear explosion.
• September – Khan writes to Prime Minister Zulfikar Ali Bhutto to offer his services and expertise to Pakistan.
• Late – Khan is tasked by UCN at Almelo with translations of the more advanced German-designed G-1 and G-2 centrifuges from German to Dutch, to which he has unsupervised access for 16 days.

Late 1970s and Early 1980s
• American intelligence officials convince Dutch authorities on two occasions not to arrest Khan for the purposes of monitoring his activities further.

• August – Pakistan begins buying components for its domestic uranium enrichment program from European Urenco suppliers. S.A. Butt, a physicist in the Pakistani embassy in Belgium, contacts a Dutch company to obtain high frequency inverters, which are used to control centrifuge motors. Purchases accelerate in the following years and many components are secured from companies in the Netherlands that Khan is familiar with.
• October – Khan is transferred away from enrichment work with FDO as Dutch authorities become increasingly concerned over his activities. He is reportedly observed asking “suspicious questions” at a nuclear trade show in Switzerland.
• 15 December – Khan suddenly leaves FDO for Pakistan with copied blueprints for centrifuges and other components and contact information for nearly 100 companies that supply centrifuge components and materials.

• Khan begins centrifuge work with the Pakistan Atomic Energy Commission (PAEC), headed by Munir Ahmad Khan.
• July – After conflicts at the PAEC, Prime Minister Bhutto gives Khan autonomous control over Pakistani uranium enrichment programs. Khan founds Engineering Research Laboratory (ERL) on July 31, which focuses exclusively on developing an indigenous uranium enrichment capability.
• The PAEC continues nuclear research and experiments in both weapons and power programs in competition with A.Q. Khan and will later develop Pakistan’s first generation of nuclear weapons.

• ERL develops working prototypes of P-1 centrifuges, adapted from the German G-1 design Khan worked with at Urenco. Pakistan enriches uranium for the first time on April 4 at Khan’s enrichment facility at Kahuta.

• April - Pakistan is cut off from economic and military assistance by the United States after U.S. intelligence learns of the recently commissioned enrichment facility at Kahuta. However, the strategic importance of Pakistan after the Soviet invasion of Afghanistan ensures that no meaningful sanctions will be imposed. This policy is consolidated following the election of Ronald Reagan in 1980.

Early 1980s
• Khan acquires blueprints for the Chinese bomb that was tested in China’s fourth nuclear explosion in 1966.
• Khan is, reportedly, approached by an unknown Arab country (possibly Saudi Arabia or Syria) requesting nuclear assistance.

• 1 May – ERL is renamed A.Q. Khan Research Laboratories (KRL) by President Zia ul-Haq in recognition of Khan’s contributions to the operational enrichment facility at Kahuta.

• Khan is convicted, in absentia, in Dutch court for conducting nuclear espionage and sentenced to four years in prison.

• Khan’s conviction is overturned based on an appeal that he had not received a proper summons. The Dutch prosecution does not renew charges because of the impossibility of serving Khan a summons given Pakistan security and the inability to obtain any of the documents that Khan had taken to Pakistan.

The Network Flows Both Ways

Mid-1980s to mid-1990s: Khan’s early successes with the Pakistani uranium enrichment program are followed by the more advanced design and technologies of the P-2 centrifuge, an adapted version of the German G-2 that can spin twice as fast as the previous P-1 design. Khan is left with an excess inventory of P-1 components and begins to purchase additional P-2 components that he will export through many of the same channels he had used to import centrifuge components. Khan makes nuclear sales in this period to Iran and offers technologies to Iraq and possibly others.

Mid 1980s
• Pakistan produces enough highly enriched uranium (HEU) for a nuclear weapon. KRL continues work on enrichment and is tasked with research and development of missile delivery systems.
• Khan, reportedly, begins to develop his export network and orders twice the number of components necessary for the indigenous Pakistani program. This transition from importer to exporter of centrifuge components is, apparently, completely missed by western intelligence services who believe Khan is only working on Pakistan’s domestic nuclear weapons program.

1986 to 1987
• Pakistan and Iran are suspected of signing a secret agreement on peaceful nuclear cooperation. Allegedly, the deal includes a provision for at least six Iranians to be trained in Pakistan at the Institute of Nuclear Science and Technology in Islamabad and the Nuclear Studies Institute. Iranian scientists might also receive centrifuge training at KRL.
• Khan is suspected of visiting the Iranian reactor at Bushehr in February 1986 and again in January 1987. These early interactions may have led directly to Khan’s assistance to Iran, but the content of the visits is unknown.

Late 1980s
• Khan and his network of international suppliers are reported to begin nuclear transfers to Iran. The period of cooperation is thought to continue through 1995 when P-2 centrifuge components are transferred. The Pakistani government claims no transfers occurred after the shipments of P-1 components and sub-assemblies from 1989 to 1991.
• German intelligence investigates potential Pakistani assistance to Iraq, and possibly Iran and North Korea, with processes related to melting uranium.

• Khan is suspected of having made an offer to Iran to provide a package of nuclear technologies, including assistance for the difficult process of casting uranium metal. The price for the package is reported to be from the tens of millions to the hundreds of millions.
• Khan is believed to make a centrifuge deal with Iran to help build a cascade of 50,000 P-1 centrifuges. In addition, Iran may have received centrifuge drawings through an unknown foreign intermediary around this time.
• KRL begins to publish publicly available technical papers that outline some of the more advanced design features Khan has developed. The papers include information that would normally be classified in the U.S. and Europe and show that KRL is competent in many aspects of centrifuge design and operation. The papers also include specifications for centrifuges with maraging steel that can spin faster than earlier aluminum designs. Later, in 1991, KRL publishes details on how to etch grooves around the bottom bearing to incorporate lubricants. These technical developments are important for Khan’s P-2 centrifuges.

• Iranian scientists are suspected of having received nuclear training in Pakistan.

• Iran is suspected of receiving its first centrifuge assemblies and components around this time. The shipped components are likely older P-1 centrifuge components that Khan no longer has use for in Pakistan. Through 1995, Khan is reported to have shipped over 2000 components and sub-assemblies for P-1, and later P-2, centrifuges to Iran.

• An Iraqi memo, found during inspections in 1995, indicates that Khan may have offered significant nuclear assistance to Iraq in late 1990. He offered to sell Iraq a nuclear bomb design and guarantee material support from Western Europe for a uranium enrichment program. Khan stated that any materials needed from Europe could be routed through a company he owned in Dubai and that a meeting with a friendly intermediary could take place in Greece. However, Iraq is believed to have turned down the offer, suspecting it to be a sting and no known follow-ups were made after the 1991 Gulf War. The investigation in the 1990s was inconclusive in its efforts to determine the authenticity of the memo.

• Pakistan begins missile cooperation with North Korea. Within Pakistan, KRL is one of the laboratories responsible for missile research and will develop the Ghauri missile with North Korean assistance. This cooperation probably establishes the connections that Khan could have used to transfer nuclear technologies. However, very little is known about when any nuclear transfers began, what nuclear components might have been obtained by North Korea, and whether or not the Pakistani government was privy to Khan’s activities.

1994 or 1995
• More advanced components for P-2 centrifuges are suspected to have arrived in Iran. B.S.A. Tahir, a Sri Lankan business man and Khan’s chief lieutenant, told Malaysian police that Iran paid approximately $3 million for these parts.

The Network Expands

Mid-1990s to the Present: After initial nuclear transfers to Iran, A.Q. Khan appears to have expanded his network of customers to include Libya and North Korea. Khan’s network was based on a complex structure of international suppliers that shipped components unimpeded by ineffective controls. Details of Libya’s acquisition trace the network to Malaysia, Singapore, Turkey, South Africa, Switzerland, South Korea, Dubai, and possibly others. Khan appears to have been financially motivated and, reportedly, received over $100 million from sales to Libya alone. Many details of the sales to Libya have been uncovered since late 2003, when it decided to come clean about its nuclear program. However many aspects of the network remain mysterious, including network sources for some necessary centrifuge components and details about suspected transfers to North Korea.

Mid 1990s
• Khan starts travel to North Korea where he receives technical assistance for the development of the Ghauri missile, an adaptation of the North Korean No Dong design. Khan makes at least 13 visits before his public confession in 2004 and is suspected of arranging a barter deal to exchange nuclear and missile technologies, though the details of any nuclear transfers remain unknown. Khan travels with military personnel from KRL. These officials could have helped with the transfer of nuclear technology because programs under the Ministry of Defense were exempt from normal export controls. The military presence at KRL, including personnel who traveled to North Korea, suggests that the Pakistani government might have been aware of Khan’s activities. President Musharraf denies this claim.
• Khan is suspected to have met with a top Syrian official in Beirut to offer assistance with a centrifuge enrichment facility.

• The Pakistani currency reserve crunch may motivate Khan to expand his nuclear network with sales to North Korea. The crisis might have made a barter agreement attractive to Pakistan to avoid defaulting on external debt. Visits of North Korean and Pakistani officials accelerate following the crisis, but it is not known if these meetings include discussions of nuclear transfers or deal exclusively with missile technologies.

• Khan begins to transfer centrifuges and centrifuge components to Libya. Libya receives 20 assembled P-1 centrifuges and components for 200 additional units for a pilot enrichment facility. Khan’s network will continue to supply with centrifuge components until late 2003.
• Khan is suspected of beginning nuclear transfers to North Korea around this time, though the dates of the first transfers are highly uncertain. Transfers to North Korea are believed to have continued through 2003, but the Pakistani government claims these transfers ceased in 2001. Over this period, Khan may have supplied North Korea with old and discarded centrifuge and enrichment machines together with sets of drawings, sketches, technical data, and depleted uranium hexafluoride.
• December – Several reports state that Pakistan's then-Chief of Army Staff General Jehangir Karamat secretly visited Pyongyang. Khan has claimed that Karamat was aware of the deal between Pakistan and North Korea to exchange enrichment assistance for missile technologies. Karamat, now Pakistan's Ambassador to the United States, says that this information is incorrect. He says that he never visited North Korea and did not have any knowledge of the proliferation activity.

• India detonates a total of five devices in nuclear tests on May 11 and 13.
• Pakistan responds with six nuclear tests on May 28 and 30.

• Pakistani government releases an advertisement of procedures for the export of nuclear equipment and components. The ad lists equipment for sale, including gas centrifuges and magnet baffles for enriching uranium. Other advertisements from KRL are reported to include an “unsubtle drawing” of a mushroom cloud and vacuum devices that attach to centrifuge casings.

• June – Peter Griffin sets up Gulf Technical Industries in Dubai, which serves as a front company for Khan’s network. B.S.A. Tahir will use Gulf Technical Industries as one of his front companies to order centrifuge components from Malaysia.
• September – Libya receives two P-2 centrifuges as demonstrator models and places an order for components for 10,000 more to build a cascade. Each centrifuge contains around 100 parts, implying approximately 1 million parts total for the entire P-2 centrifuge cascade.

• Libya obtains 1.87 tons of uranium hexafluoride, the gas that is used to feed enrichment centrifuges. The amount is consistent with that required for a small pilot enrichment facility. The source of the uranium hexafluoride remains uncertain. In 2004, evidence emerges that North Korea might have supplied Libya with the material, which would be the first discovered transfer of nuclear material from North Korea to an A.Q. Khan network recipient. The evidence remains inconclusive, however, and authorities continue to suspect that the uranium hexafluoride came from Pakistan.
• March – Khan is forced into retirement. Khan refuses the compensatory position of “advisor to the chief executive” and is later given the ceremonial title of “Special Advisor to the Chief Executive on Strategic and KRL Affairs.” However, neither Khan nor the press use this title. President Musharraf has admitted that Khan’s suspected proliferation activity was a critical factor in his removal from KRL.
• Summer – American spy satellites detect missile components being loaded into a Pakistani cargo plane outside of Pyongyang. Intelligence services assume the cargo to be missile technology traded in direct exchange for nuclear technology, but no hard evidence exists.
• December – B.S.A. Tahir signs a $13 million contract with Scuomi Precision Engineering (SCOPE) in Malaysia for 25,000 aluminum centrifuge components. The components will be shipped to front companies in Dubai, including Gulf Technical Industries and SMB Computers. SCOPE representatives later acknowledge manufacturing parts for Tahir, but believed that they would be used in Dubai oil and gas industries.

Late 2001 or Early 2002
• Libya receives blueprints for nuclear weapons plans. The plans are reported to be of Chinese origin with Chinese notes in the margins. There is reported to be a note on the blueprints that “Munir’s bomb would be bigger,” possibly a reference to Munir Ahmad Khan of the PAEC, who was in competition with A.Q. Khan to develop a Pakistani bomb.

• December – Shipments begin from SCOPE of aluminum centrifuge components. Four shipments are believed to have been sent from Malaysia to Dubai before August 2003, en route to Libya.

• Spring – The State Department announces some sanctions against KRL, citing illegal missile transactions. The State Department also states that it has insufficient evidence to issue sanctions for illegal nuclear transactions.
• April – German authorities intercept a ship in the Suez Canal with a large cargo of strong aluminum tubing en route to North Korea. The tube specifications suggest that they are intended for use as outer casings for P-2 centrifuges.
• October – The German cargo ship BBC China is intercepted en route to Libya with components for 1,000 centrifuges. The parts were manufactured in Malaysia by SCOPE and shipped through Dubai.
• December – Libya renounces its nuclear weapons program and begins the process of full disclosure to the IAEA, including the declaration of all foreign procurements.

• 4 February – Khan makes a public confession on Pakistani television (in English) of his illegal nuclear dealings. Khan claims that he initiated the transfers and cites an “error of judgment.” He is pardoned soon after by President Musharraf and has been under house arrest since. The Pakistani government claims that Khan acted independently and without state knowledge.
• March – A container aboard the BBC China (the ship that was previously intercepted) arrives in Libya with one additional container of P-2 centrifuge components. Colonel Qaddafi reports the arrival to American intelligence and the IAEA. The Libyans warn American officials that not all of the components from Libya’s orders had arrived and some might still show up in the future.

Chronology by Michael Laufer at the Carnegie Endowment for International Peace.