On February 4, 2004, the Pakistani scientist Abdul Qadeer (A.Q.) Khan, then famous for his role in developing Pakistan’s nuclear arsenal, confessed on live television to having illegally proliferated nuclear weapons technology to Iran, Libya, and North Korea over the course of decades. Today Khan is enjoying a resurrection at home, where he is again touted as the “Mohsin e-Pakistan,” or the savior of Pakistan. He appears as the guest of honor at official ceremonies, and last year Sir Syed University of Engineering and Technology declared him a distinguished alumnus in recognition of his “meritorious services and valuable contributions towards scientific research and its practical application for the productive use for mankind.”

Outside of Pakistan, Khan has largely been forgotten, despite the fact that his fingerprints are all over the world’s most volatile nuclear hot spots. Indeed, three of the United States' most significant national security challenges—Iran, North Korea, and Pakistan—are largely the results of Khan's handiwork. 

Between the start of Khan’s nuclear black market in the mid-1970s and his forced confession in 2004, the United States and other countries had many opportunities to stop him. Yet each time, policymakers decided that preventing the spread of nuclear weapons was less important than pursuing other foreign policy goals. These decisions haunt U.S. leaders today. Pakistan’s nuclear deterrent makes it impossible for U.S. commanders to force the country to close its safe havens for Afghan extremists. Iran’s nuclear program—though frozen for now—could still lead to a nuclear arms race in the Middle East. And North Korea, which Khan helped turn from a thorn in the world’s side into an unstable nuclear power, now threatens the lives of millions.

How were Khan’s activities allowed to continue for so long? And what lessons might the failures to contain him hold for policymakers today?

A.Q. Khan waves from his house in Islamabad, August 2009.
A.Q. Khan waves from his house in Islamabad, August 2009.
Mian Kursheed / Reuters


Born in British India in 1936, Khan fled with his family for Pakistan during the partition in 1948. A good student, he earned a doctorate in engineering from Belgium’s Catholic University of Leuven in 1972 and subsequently landed a job as a metallurgist at a uranium enrichment plant in the Netherlands, where advanced work was being done on enrichment for civilian reactors.

Khan was working at the plant in 1974 when India tested its first nuclear weapon. The episode inflamed Khan’s nationalism, and he began looking for a way to help Pakistan match its rival. His initial letters to Pakistani officials were ignored. But in August 1974 the prime minister, Zulfikar Ali Bhutto, took notice of a letter from Khan. Bhutto asked the Pakistani embassy in the Netherlands to contact him, and by the fall of 1974 Khan was secretly copying designs for centrifuges and compiling a list of potential companies that could provide Pakistan with the technology to produce highly enriched uranium for nuclear weapons.  

Khan could have been stopped at this early stage. In mid-1975, Dutch security police monitored a meeting between him and a Pakistani diplomat suspected of seeking nuclear technology. The police believed they had enough evidence to arrest Khan. But after consulting with senior Dutch government officials and the CIA, they decided to keep him under surveillance in hopes of learning more about Pakistan’s nuclear-smuggling network. While the CIA and Dutch intelligence watched, Khan managed to complete his theft of the centrifuge designs. Whether he was alerted to the surveillance or simply felt he had what he needed, Khan and his family abruptly left the Netherlands for Pakistan in December 1975.

There are two basic paths to the fissile material that forms the explosive core of a nuclear weapon. The first is to process plutonium, a byproduct of a nuclear reactor, into fissile material. The second is to use high-speed centrifuges to enrich uranium to weapons-grade material, called highly enriched uranium (HEU).

Khan’s fingerprints are all over the world’s most volatile nuclear hot spots.

At the time of Khan’s return, Pakistan had been trying the plutonium route. But its scientists lacked the expertise and were making no real progress. Khan offered an alternative: use the stolen centrifuge designs and tap into the network of potential suppliers in Europe. After some initial skepticism, the Pakistanis gave him a research facility and unfettered freedom. He began building centrifuges to produce the HEU for nuclear weapons, aided by a constant flow of advanced technology from European suppliers.


By the late 1970s, the United States and other governments were aware of Pakistan’s nuclear efforts and Khan’s progress in enriching uranium. On April 6, 1979, U.S. President Jimmy Carter imposed economic sanctions on Pakistan in an effort to halt its nuclear progress. The Carter administration also used its influence to block loans to Pakistan from the World Bank and pressure France and others to stop selling the country nuclear technology.

It is unclear if these pressures would have eventually stopped Pakistan’s nuclear program, because on Christmas Eve 1979, the Soviet Union invaded Afghanistan. For years, the United States had been providing limited covert assistance to groups trying to overthrow the Soviet-backed regime in Kabul. Now, after the invasion, Carter’s national security adviser, Zbigniew Brzezinski, saw a chance to weaken the Soviets by sending more cash and weapons to the guerrillas.

To do so, the Americans would need a base of operations. In a December 26 memo to Carter, Brzezinski argued that neighboring Pakistan was the perfect candidate. Expanding operations in Afghanistan, he wrote, “will require a review of our policy toward Pakistan, more guarantees to it, more arms aid, and, alas, a decision that our security policy toward Pakistan cannot be dictated by our nonproliferation policy.” The United States, that is, would have to look the other way on Pakistan’s nuclear program. Carter agreed. He lifted the sanctions on Pakistan and kicked in $400 million in economic and military aid.

Carter’s decision opened the door to Pakistan’s pursuit of nuclear weapons—the country would go on to successfully test its first bomb in 1998. During a television interview in 2009, Khan himself said that the Soviet-Afghan war “provided us with space to enhance our nuclear capability. Given the U.S. and European pressure on our program, it is true that had the Afghan war not taken place at that time, we would not have been able to make the bomb as early as we did.”

Nearly four decades later, the United States is living with Carter’s decision. The U.S. war in Afghanistan drags on today, at a cost of billions of dollars and thousands of lives, partly because extremist groups can flee to safety in Pakistan. The United States cannot force Pakistan to eradicate these safe havens because Islamabad can fall back on the ultimate threat, its nuclear arsenal. But Khan did not stop at developing a bomb for Pakistan. Instead, he went on to create a global nuclear black market.

North Koreans celebrate the successful test of an ICMB in Pyongyang's Kim Il Sung Square, July 2017.
KCNA / Reuters


One person who had an inside look at Khan’s network was Benazir Bhutto. Sitting in her living room in late 2003 during her exile in Dubai, the former two-time Pakistani prime minister (who was assassinated in 2007) recounted to the authors how she learned of Khan’s role in Iran’s nuclear program and how she became an unwitting midwife to his relationship with North Korea.

As Bhutto recalled it, she was on an official trip to Tehran in late 1989, her second year as prime minister, when Iranian President Akbar Hashemi Rafsanjani took her aside during a state dinner. He explained that the military leaders of their two countries had agreed to a defense pact that included Pakistan’s help with nuclear weapons technology. Bhutto said she was blindsided. (U.S. intelligence reports from that period concluded that the military had shut her out of its nuclear weapons program.)

Bhutto said she summoned General Mirza Aslam Beg, the head of the Pakistani armed forces, to her office when she returned to Islamabad. He denied any knowledge of an agreement or a transfer of nuclear capabilities. Bhutto told us she was certain he was lying but was too weak politically to challenge the military. She took a half measure, ordering that no nuclear scientist be permitted to travel outside Pakistan without her approval, an order confirmed by one of her aides at the time.

By the late 1970s, the United States and other governments were aware of Pakistan’s nuclear efforts and Khan’s progress in enriching uranium.

Bhutto was right to feel vulnerable—she was ousted as prime minister less than a year later. By then, Khan had traveled to Iran to lay the groundwork for the country’s first uranium enrichment plant at Natanz. While the precise dates are unclear, subsequent investigations by the International Atomic Energy Agency (IAEA) and others found that Khan’s first contact with Iran occurred in 1987 and that by the late 1980s Khan and his network were supplying nuclear technology to Iran’s fledgling program. Before the end of the decade, Khan had sent Iran over 2,000 components and assemblies for centrifuges to enrich uranium—a flow that continued until the mid-1990s.

Khan’s network started with a handful of companies in Switzerland and Germany willing to exploit lax export controls. He also developed strong ties to engineers and other experts in Germany, the Netherlands, Switzerland, and the United Kingdom. Eventually he was producing components in factories in Malaysia and South Africa and maintained a shipping hub in Dubai. During the 1990s, however, Khan’s smuggling operation remained under the radar of the United States, which was focused on the possibility of Russia providing nuclear secrets to Iran.  

In 1993, Bhutto became prime minister a second time. Within weeks, Khan was on her doorstep. In our interview, Bhutto recalled Khan asking her to make a side trip to North Korea during her state visit to China in 1994. She claimed he said he wanted help with “this nuclear thing.” When Bhutto asked what he meant, Khan said that he wanted North Korean expertise for a missile he was developing to carry a nuclear payload. Bhutto wanted to improve her standing with Pakistan’s military, so she agreed. “I thought the military would be very happy with me and would stop trying to destabilize my government,” she told us. The former prime minister maintained in our interviews that Pakistan paid for the designs for North Korea’s Nodong missile. She said she had ruled out providing nuclear technology to North Korea.  

Her testimony, however, was contradicted by Khan himself. During the mid-1990s, U.S. intelligence observed Khan making 13 trips to North Korea, often with shipments aboard Pakistani military aircraft. And in his 2004 confession, Khan admitted that he transferred nuclear technology to Iran, Libya, and North Korea, though he later retracted his statement.


For North Korea, Khan’s assistance arrived at a critical moment. Like Pakistan, North Korea focused initially on processing plutonium from its two civilian reactors into fissile material for weapons. But reactors are massive installations that are visible to aircraft and satellites. By the early 1990s, U.S. intelligence and the IAEA had detected North Korea’s program. In 1994, the United States and North Korea negotiated a freeze of the North’s program in exchange for oil and food under a deal known as the Agreed Framework. Monitoring the agreement would be relatively straightforward: the reactors were in plain sight of inspectors from the IAEA and could be monitored from the air. North Korea was stuck.

Khan provided North Korea with an alternate path to nuclear weapons. Unlike a reactor, centrifuges are small and can be concealed in underground facilities and tunnels inside mountains (something at which the North Koreans are quite skilled). These centrifuges allowed North Korea to continue developing a secret stockpile of fissile material despite the Agreed Framework and UN sanctions.

Although North Korea has conducted multiple nuclear tests in recent years, international monitoring has not determined whether the fissile material comes from plutonium or HEU. But in 2010, the North Koreans surprised the world by inviting Siegfried Hecker, a leading U.S. nuclear expert, to visit a previously unknown installation holding 2,000 centrifuges. The North Koreans claimed the centrifuges were for low-grade enrichment to power a new reactor to produce electricity. But Hecker wrote that the facilities “could be readily converted to produce highly enriched uranium bomb fuel.”

Former Iranian President Mahmoud Ahmadinejad at the Natanz nuclear enrichment facility, April 2008.
Former Iranian President Mahmoud Ahmadinejad at the Natanz nuclear enrichment facility, April 2008.


Khan’s smuggling career ended with his confession on February 4, 2004. By then, the U.S. attitude toward Khan and Pakistan’s nuclear proliferation had changed. The 9/11 attacks raised fears that al Qaeda or some similar group could get their hands on a nuclear device or build their own with help from someone like Khan. Irrefutable proof of Khan’s activities came from evidence seized in 2003 when the U.S. Navy intercepted a ship carrying nuclear technology from one of Khan’s factories to Libya.   

Pakistani President Pervez Musharraf forced Khan to confess. But, faced with angry nationalists and a restive military, Musharraf softened the blow the next day by pardoning Khan, leaving only a slap on the wrist of five years under house arrest. In 2008, Khan retracted his confession, though he has boasted about helping Iran and North Korea at other points.

The damage he did remains. Driven by ego, nationalism, and a skill for subterfuge, Khan built a clandestine global network that increased the danger of a nuclear catastrophe. Worse, he was never forced to identify the participants in his black market. Policymakers and intelligence agencies simply do not know the full extent of his ring, which means they can never close the file on the dangers.

The IAEA was blocked at every turn when it tried to track down the participants and determine just how much nuclear knowledge was loose in the world. Companies, bankers, governments, and individuals refused to cooperate. Some feared legal jeopardy. Others wanted to avoid embarrassment.

The worst offenders were Pakistan and the United States. Musharraf refused to allow the IAEA or anyone to interview Khan after his confession. Instead, he forbade him to leave Pakistan for fear he might be arrested and interrogated. The United States, for its part, did not pressure the Pakistanis to make Khan reveal his secrets. In an echo of Carter’s decision to turn a blind eye to Pakistan’s nuclear efforts, President George W. Bush did not want to risk his already tenuous relationship with Islamabad with a war raging next door in Afghanistan.

But the Bush administration went further. The CIA, with lobbying help from then Attorney General Alberto Gonzales and Secretary of State Condoleezza Rice, persuaded the Swiss government to destroy a staggering trove of documents and digital plans confiscated from three of Khan’s longtime accomplices in Switzerland. The material was a road map to participants in the ring and an inventory of the technology pumped into the black market, including advanced weapons designs. The CIA was trying to protect the accomplices, who had been paid $10 million for informing on Khan near the end of his operations. A senior IAEA official literally stood by as 1.9 tons of paper were shredded and burned in an incinerator in Bern along with dozens of computer hard drives over two days in February 2008.

There are other lessons to be learned from the Khan affair. Stopping the spread of nuclear weapons technology and tightening export laws should be a top priority for every government. A single nuclear device detonated by a state or terrorist group will change our world forever. Similarly, policymakers should push to make trafficking in nuclear weapons technology a crime against humanity because national governments cannot be counted on to do the right thing.

Khan may eventually be relegated to the dustbin of history. But the lessons learned from his crimes must be addressed before it’s too late.

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