Stemming the spread of nuclear weapons

The author discusses what is being done to prevent the spread of nuclear weapons. He says that two mechanisms need to be strengthened: international safeguards to ensure that civilian nuclear materials and technology are not diverted to military purposes, and controls on the export of such materials and technology. While 135 nations signed the 1970 Non-Proliferation Treaty (NPT), it is not enough. Detecting diversion of nuclear materials to the manufacture of nuclear weapons or explosives is not easy. It is also difficult to enforce safeguard systems when countries are exporting nuclear technology and materials. The author says nuclear-weapon states need to agree to a complete test ban to convince other nations to give up trying to acquire nuclear weapons.