NUCLEAR, BIOLOGICAL AND CHEMICAL WEAPONS
October 9, 2009: Israel has asked Russia to get several Russian scientists to stop working on Iran's nuclear weapons program. The Israeli prime minister recently went to Russia and personally delivered the evidence, and a plea for help in halting the work of the Russian experts. Israel believes that the Russian scientists could not work in Iran without the permission of the Russian government. U.S. and British intelligence experts are dubious about freelance Russian nuclear weapons experts being in Iran, but Israel apparently has evidence that they felt might motivate the Russian government to help out.
Iran is believed to have received technical help from several different sources, including Pakistan (the Khan network), China (as payment for oil field development rights in Iran) and North Korea (for cash). The general design of a nuclear bomb is pretty simple. But the nuclear bomb itself is a precision instrument, and while many people have the design worked out in detail, to make it work, and work reliably, you need manufacturing equipment and components that are very difficult to obtain, and use, properly. Once you have all the required components, it's even more difficult to assemble them all correctly. It's the manufacturing and assembly of the components that prevents most nations from building nuclear weapons, as well as not having the right type of nuclear material (plutonium or highly enriched uranium).