Stopping proliferation of nuclear weapons, especially to unstable countries or terrorist groups, has been a major concern of governments. Because of their extreme danger, it is illegal under international treaties to sell or transport materials associated with nuclear weapons. However small the chance of misusing nuclear weapons, the potential damage is so great that the risk cannot be ignored. Therefore, how to understand and thwart anyone who would try to evade the restrictions on nuclear technology is a high priority for intelligence analysts.

In the early 1970s, Abdul Qadeer Khan (1936–), a metallurgist from Pakistan, was working in the Netherlands when the Pakistani government announced that it was determined to acquire nuclear weapons in an effort to achieve deterrence and strategic equality when dealing with its giant rival, India. Pakistan had just lost another war with India, which had led to the dismemberment of the country and the founding of the independent state of Bangladesh. As it turned out, the company for which Khan worked enriched uranium into fuel for reactors, a technology that could also be used to produce nuclear weapons.

In September 1974, Khan wrote a letter to the Pakistani government offering to help in the development of a nuclear weapon. Islamabad accepted his proposal, and before departing for home Khan stole or copied a large number of blueprints for equipment that could be used to enrich uranium.