'CIA in 1970s knew about Sino-Pak nuclear cooperation'

By late 70s, the CIA knew that China had aided Pakistan's nuclear weapons programme by providing it with weapons design information, according to just declassified US documents.
According to recently declassified State Department Bureau of Intelligence and Research (INR) reports by the National Security Archive and the Nuclear Proliferation International History Project, a few years after China's first nuclear test in October 1964 INR wondered whether China would help Pakistan, among other countries, acquire a nuclear capability.
INR experts believed China had limited resources and seemed "cautious and indecisive" on the question of nuclear assistance, but they saw "reasons for continued concern".

A year later, intelligence reports concerning visits to China by Pakistani defence and science advisers sparked the question, "will Communist China give nuclear aid to Pakistan?"
INR analysts downplayed their significance, arguing that both countries would see risks in nuclear weapons cooperation, although assistance for peaceful purposes was possible.
One of the visitors to China, presidential science adviser Abdus Salam, who was later awarded Nobel Prize in theoretical physics, later played a central role in the 1972 Pakistani nuclear weapons decision, but INR could not foresee that, the National Security Archive said in a media release yesterday.

In a report to the Secretary of State, the then INR Director Thomas Hughes had said that "several recent developments raised the possibility that Pakistan and Communist China may have entered into some sort of an agreement for collaboration on nuclear matters."

"We have two reports from Pakistanis that an agreement for unspecified Chinese assistance in the nuclear field was obtained during the recent visit of Defence Adviser Ghulam Faruque and Science Advisor Abdus Salem to Peking," he wrote.
"We have no supporting evidence of Sino-Pakistani nuclear collaboration although there is little reason to expect that we would have it at this time," Hughes had said.
INR analyst Thomas Thornton concluded that Pakistan was highly unlikely to seek a significant degree of Chinese nuclear assistance as it would cause severe strains in US relations with Pakistan and there were "few things that would be as certain to trigger an Indian decision to produce nuclear weapons as would a Sino-Pakistani arrangement for nuclear arms collaboration."

Moreover, China was unlikely to be responsive. "We remain unconvinced by the evidence thus far obtained that there is any definite plan for Sino-Pakistani cooperation of any type in the nuclear area, but if there is, it is most likely in the peaceful area," he wrote.
Whether Salam, who was later ostracised because of his adherence to a minority Muslim sect, played an affirmative role in the then Pakistan Prime Minister, Zulfikar Ali Bhutto's decision in 1972 to build the bomb has been a matter of controversy.
Moreover, once Bhutto had made the decision to go ahead, Salam recruited top scientists to help carry it out, said the National Security Archive.