During the late 1970s, for example, the CIA acquired information suggesting and later confirming that China had aided the Pakistani nuclear weapons program by providing it with weapons design information. According to recently declassified State Department Bureau of Intelligence and Research (INR) reports published today by the National Security Archive and the Nuclear Proliferation International History Project, years earlier, not long after China's first nuclear test (October 1964), INR wondered whether China would help Pakistan, among other countries, acquire a nuclear capability. INR experts believed that 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 defense 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 Beijing, the future Nobel Prize winner Abdus Salam, later played a central role in the 1972 Pakistani nuclear weapons decision, but INR could not foresee that.
Document 19: Thomas L. Hughes to the Secretary, "Will Communist China Give Nuclear Aid to Pakistan?" 12 August 1966, Intelligence Note 506, Secret, Distribution List Attached
Source: RG 59, UD-UP 131, Bureau of Intelligence and Research, Reports Coordination and Review Staff, Intelligence Reports, 1961, 1963-67, box 2, IN-500-579