The uranium transfer in five stainless-steel boxes was part of a broad-ranging, secret nuclear deal approved years earlier by Mao Zedong and Prime Minister Zulfiqar Ali Bhutto that culminated in an exceptional, deliberate act of proliferation by a nuclear power, according to the accounts by Khan, who is under house arrest in Pakistan.
U.S. officials say they have known about the transfer for decades and once privately confronted the Chinese -- who denied it -- but have never raised the issue in public or sought to impose direct sanctions on China for it. President Obama, who said in April that "the world must stand together to prevent the spread of these weapons," plans to discuss nuclear proliferation issues while visiting Beijing on Tuesday.
According to Khan, the uranium cargo came with a blueprint for a simple weapon that China had already tested, supplying a virtual do-it-yourself kit that significantly speeded Pakistan's bomb effort. The transfer also started a chain of proliferation: U.S. officials worry that Khan later shared related Chinese design information with Iran; in 2003, Libya confirmed obtaining it from Khan's clandestine network.
