Jeffrey LewisThe Chinese Nuclear Weapons Design That Ended Up in Libya

David Albright and Corey Hinderstein have an article, Unraveling the A. Q. Khan and Future Proliferation Networks, in The Washington Quarterly that has previously upublished information about the Chinese nuclear weapons design provided to Libya by the Khan network:

The documents appear to have been information that Pakistan had received in China in the early 1980s. They include detailed, dated, handwritten notes in English taken during lectures given by Chinese weapons experts who were named by the notetakers. These notetakers appear to have been working for Khan, based on their cryptic notations deriding a rival Pakistani nuclear weapons program led by Munir Khan, the chairman of the Pakistan Atomic Energy Organization. The design appears to be for a Chinese warhead that was tested on a missile, has a mass of about 500 kilograms, and measures less than a meter in diameter.

The documents were previously described in The Washington Post.

Update: Bill Burr reminds me that the National Security Archive has a treasure trove of documents related to US assessments of Chinese nuclear weapons assistance to Pakistan—including a 1983 State Department analysis that concluded that Sino-Pakistani “cooperation has taken place in the area of fissile material production and possibly also nuclear device design.”