Earlier this year, it was revealed that Pakistan had been selling nuclear information to some of the world's most dangerous and unstable regimes. The blame was pinned on one scientist, Abdul Qadeer Khan, and the US authorities acted as surprised as anyone. But according to many experts, there is little way the Bush administration could not have known about the proliferation: "It was certainly apparent to French intelligence," claims investigative journalist Joseph Trento. "They were convinced that the US was deliberately not acting on any of this. Virtually everybody in Western intelligence knew about what Khan was doing."

America's policy of turning a blind eye to Pakistan's nuclear proliferation is nothing new. In a 1979 memorandum to President Carter, National Security Advisor Zbigniew Brzezinski stressed the importance of securing Pakistan's support against the Soviets in Afghanistan. "Our security policy toward Pakistan cannot be dictated by our non-proliferation policy," he advised. "We made a deal with the devil," states Trento. 'They wanted to develop the weapons, we wanted to beat the Soviets. In order to do that we made a trade-off."

CIA sources suspect that up to half the funding for the Afghan resistance ended up being diverted to fund Pakistan's nuclear bomb. With so much cash flying about, money trails were impossible to trace. But one source of nuclear funding that has been traced came from Saudi Arabia. "There is a clear trail through bank receipts that it was being funded, to some extent, by Saudi money," states US Counter Intelligence Expert Mike Pilgrim.

But the US seemed relatively unconcerned about Saudi Arabia's nuclear agenda - even when faced with hard evidence of their determination to build an atomic bomb. In 1994, a high level Saudi defector, Mohammed al-Khilewi, offered America 14,000 photocopied documents exposing Saudi Arabia's nuclear plans. These included instructions to diplomats on "how you can sneak in bomb-making material through diplomatic pouches." But incredibly, the FBI agents who debriefed him were instructed not to accept the documents on offer.

More worryingly, it wasn't just the Saudis colluding with Pakistan. In the late 1990s rumours started emerging of Pakistani scientists meeting with al-Qaida operatives in Afghanistan. BBC correspondent Rahimullah Yusaf Zai is one of the few journalists to get close to Bin Laden. He met him twice and on both occasions was told "Look, according to the Holy Koran ... the Muslims must upgrade their defences. They must be ready to meet any challenges by their enemies."

Nuclear secrets have also been shared with Malaysia, Iran and Libya. Religious parties in Pakistan have taken great delight in describing the nuclear network as 'The Islamic Bomb'. "They say this is a bomb that should be used for the collective defence of Islam everywhere," states Pakistani nuclear scientist Professor Pervez Hoodbhoy. He believes the situation in Pakistan is now dangerously unstable. "I fear that if Musharraf is assassinated there could be a dangerous situation in the country and the nuclear weapons then would possibly be hijacked."

With Pakistan now armed and their nuclear technology shared with other countries, it is impossible to now tell how much damage has been done. But, in the words of Joseph Trento: "Where you have Saudi interests and Pakistani interests and al-Qaida interests converging, it's a very frightening picture."

Keyshots: Pakistani nuclear parade, Iranian Hostage crisis, Brezinsky, Afghan mujahaddin, wrecked Soviet helicopter, bin Laden, thousands of US dollars handed to mujahaddin, Riyadh aerials, Saudi royal family and officials.