Foreign Assistance
In the past, China played a major role in the development of Pakistan's nuclear infrastructure, especially when increasingly stringent export controls in western countries made it difficult for Pakistan to acquire materials and technology elsewhere. According to a 2001 Department of Defense report, China has supplied Pakistan with nuclear materials and expertise and has provided critical assistance in the construction of Pakistan's nuclear facilities.
In the 1990s, China designed and supplied the heavy water Khusab reactor, which plays a key role in Pakistan's production of plutonium. A subsidiary of the China National Nuclear Corporation also contributed to Pakistan's efforts to expand its uranium enrichment capabilities by providing 5,000 custom made ring magnets, which are a key component of the bearings that facilitate the high-speed rotation of centrifuges.
According to Anthony Cordesman of CSIS, China is also reported to have provided Pakistan with the design of one of its warheads, which is relatively sophisticated in design and lighter than U.S. and Soviet designed first generation warheads.
China also provided technical and material support in the completion of the Chasma nuclear power reactor and plutonium reprocessing facility, which was built in the mid 1990s. The project had been initiated as a cooperative program with France, but Pakistan's failure to sign the NPT and unwillingness to accept IAEA safeguards on its entire nuclear program caused France to terminate assistance.
According to the Defense Department report cited above, Pakistan has also acquired nuclear related and dual-use and equipment and materials from the Former Soviet Union and Western Europe.
Go back to pre 9/11 era and feel the egg hitting you face. 
