While the Chinese government can say that it will not assist other nations in developing nuclear weapons, and mean it, the government does not have a lot of control over what thousands of Chinese companies do. For a police state, controlling the news, and what people do on the Internet is more important than scrutinizing thousands of exports by Chinese firms (who are encouraged to do what ever they can to grow their businesses and provide jobs.) Case in point is North Korea receiving twenty tons of tributyl phosphate from a Chinese supplier earlier this month. Tributyl phosphate is used in the manufacture of plastics, as an anti-foaming agent and to manufacture fire retardant hydraulic fluid. It is also used to extract Plutonium for the manufacture of nuclear weapons. At the moment, the only industry in North Korea that has any use for tributyl phosphate is the government program to make nuclear weapons.