Once again, the sobering truth has been revealed. The black market for nuclear weapons is flourishing, and international monitoring mechanisms have failed to expose them. For 15 years, the "father of the atom bomb in Pakistan," Dr. Abdul Qadeer Khan, operated a worldwide network of agents and middlemen who sold Pakistan's nuclear secrets to North Korea, Iran and Libya. And it was only the decision of these two last countries to subject their nuclear programs to external monitoring that exposed the existence of this secret network.

Even though dozens of people in over 10 countries were involved in this illegal network, the International Atomic Energy Agency (IAEA), which serves as the UN's watchdog with respect to nuclear proliferation, was entirely taken aback by the disclosures. "This is the most dangerous phenomenon which we have witnessed for some time in the area of nuclear proliferation," IAEA Director-General Dr. Mohamed El Baradei said. As it turns out, Khan sold equipment used in producing enriched uranium to Iran, Libya and North Korea. Libya even received blueprints and instructions relevant to the production of nuclear weapons - such assistance would have made it easier for it to develop nuclear weapons.

Khan appeared last week on Pakistani state television and asked for forgiveness. In accord with a recommendation formulated by Pakistan's cabinet, the country's president, Pervez Musharraf, decided to pardon the scientist and emphasized that Khan's activities were not conducted with the government's knowledge. However, nobody really believes that in Pakistan, where the army maintains strict control over nuclear activity, the country's leadership did not know about Khan's secret activities. Moreover, it is known that some of the nuclear-related equipment was sent from Pakistan on planes belonging to the country's air force. For his part, Khan, who received millions of dollars from nuclear transactions, maintains a lavish lifestyle; and it's hard to believe that Musharraf didn't grasp that a nuclear scientist needed to be bringing in income from special sources to enjoy such a prodigal way of life.

And that's the troubling point of this whole story: here's an example of a country whose regime is unstable and possesses nuclear weapons going off to sell know-how and components for the production of bombs to a state with an extremist regime. Worse, nobody really knows to whom exactly the Pakistani nuclear secrets were sold. Disclosures that have surfaced in past days about Khan's activities are just "the tip of the iceberg," El Baradei warns.

It is indeed becoming clear that the network was wider than what had been thought. Middlemen, buyers, sellers and manufacturers operated in Germany, Holland, Belgium, South Africa, Japan, Malaysia, the United States, Russia, China and, of course, Pakistan. Diplomats believe that other states will be added to this list. It can be assumed that authorities in some states turned a blind eye to the activities, or were even actively involved in them. For instance, in Malaysia, the major stockholder of one company involved in the network is the son of the country's prime minister, Abdullah Ahmad Badawi.

The most disturbing fear stems from the possibility that technology and equipment reached terror organizations. Many elements in Pakistan's society, including army officers, sympathize with Islamic terror organizations, and many continue to support Osama bin Laden and the Taliban. Searches of Al-Qaeda offices in Afghanistan revealed documents indicating that operatives from the terror organization invested tremendous effort to develop a "dirty" radioactive bomb. Investigators now suspect that the "Pakistani connection" with terror played out in the nuclear sphere.

In 2001, two Pakistani nuclear scientists, Sultan Bashiru-Din Mehmood and Abdul Majid, were detained on suspicion that they had sold nuclear secrets to the Taliban and to Al-Qaeda. At the time, experts also reasoned that the two could never have made such sales without the Pakistani authorities' knowledge. In the end, the two were acquitted.

Centrifuge production equipment cannot really help terror organizations - its use in the production of enriched uranium depends on the availability of huge facilities and hundreds of technicians. But, according to David Albright, an expert on nuclear proliferation, the purchase of blueprints and instructions for nuclear bomb production can be a significant step, making it easier for a terror organization to attain nuclear capability. If a terror organization with details relating to the production of a nuclear bomb manages to get its hands on 50-to-100 kilograms of enriched uranium, it will be able to build a bomb similar to that which was dropped on Hiroshima.

The Khan affair illustrates anew the extent to which a black market in nuclear weapons is alive and kicking. El Baradei, whose lenient policies toward "nuclear criminals" has given a real boost to this black market, warned last week that recent disclosures regarding Pakistan point to serious flaws in international anti-proliferation mechanisms. "What is needed is a general review of systems for monitoring the export of nuclear equipment and technology," he said. "To monitor proliferation, what we have today is a small group of states which operate on the basis of a `gentlemen's agreement' - and it isn't working."

It can only be hoped that such words will be heard, particularly in Europe, and that they will promote new, more determined forms of monitoring to prevent nuclear proliferation. If this doesn't happen, the world will become a much more dangerous place.