In the late 1970s, Central Intelligence Agency had information that China might have provided a fairly comprehensive package of proven nuclear weapons design information to Pakistan, a recently declassified document has revealed.
According to recently declassified CIA data, obtained by the National Security Archive under the Freedom of Information Act, the CIA had evidence suggesting close Pakistan-China nuclear cooperation, to the point of facilitating a nuclear weapons capability, although the intelligence community saw this as possibly a special case based on an alliance that had existed since 1963.
"This allegation has come up before, for example in a State Department document and in major news stories but this is the first time the CIA has released some of its own information," according to the set of two documents obtained by the National Security Archive.
"The estimate highlights some of the main developments, including "verbal consent (in 1974) to help Pakistan develop a 'nuclear blast' capability", "hedged and conditional commitment" in 1976 to provide nuclear weapons technology, and unspecified excised information that raised the "possibility that China has provided a fairly comprehensive package of proven nuclear weapon design information," the NSA said.
"Even without Chinese help, the Pakistanis could develop a nuclear weapon, but access to Chinese weapons design and test data might be crucial in establishing Islamabad's confidence in an untested weapons capability," said a 1983 national intelligence estimate of the CIA, which is heavily excised.
The exchanges may not have been one-way and the reference to Chinese "involvement" in Pakistan's uranium enrichment programme probably refers to gas centrifuge technology, which Pakistan shared with the Chinese, it noted.
Significant portions of the document covering technology sharing are excised, but more may be learned if additional details are released under appeal, the NSA added.
With nuclear proliferation a policy priority for the Jimmy Carter administration, and Pakistan already a special concern, the possibility that China and Pakistan were sharing nuclear weapons-related information began worrying US government officials, NSA said.
However, the CIA had no hard evidence -- and the soft evidence that concerned them is massively excised in the December 1979 report just as Beijing and Washington were normalising relations-so the "precise nature and extent of this cooperation is uncertain," the NSA said.
"These concerns did not go away during the Reagan administration. While nuclear proliferation was not a top priority, the administration was apprehensive about the implications of the spread of nuclear capabilities and that China may have been aiding and abetting some potential proliferators by selling non-safeguarded nuclear materials," NSA said.