What prevents more countries from creating nuclear weapons?
Ezra: It's trivial to design and build a nuclear weapon.The trick, as others have mentioned, is getting the Uranium.You do not need billions in R&D, or a crack team of scientists.A working bomb was actually designed by two (ableit, smart) students...  in 30 months... in 1964.  It would be far easier today.Check: http://www.guardian.co.uk/world/2003/jun/24/usa.science"You could have taken any number of classes at Beloit with Professor Dobson, until his recent retirement, without having any reason to know that in his mid-20s, working entirely as an amateur and equipped with little more than a notebook and a library card, he designed a nuclear bomb.Today his experiences in 1964 - the year he was enlisted into a covert Pentagon operation known as the Nth Country Project - suddenly seem as terrifyingly relevant as ever. The question the project was designed to answer was a simple one: could a couple of non-experts, with brains but no access to classified research, crack the "nuclear secret"? In the aftermath of the Cuban missile crisis, panic had seeped into the arms debate. Only Britain, America, France and the Soviet Union had the bomb; the US military desperately hoped that if the instructions for building it could be kept secret, proliferation - to a fifth country, a sixth country, an "Nth country", hence the project's name - could be averted. Today, the fear is back: with al-Qaida resurgent, North Korea out of control, and nuclear rumours emanating from any number of "rogue states", we cling, at least, to the belief that not just anyone could figure out how to make an atom bomb. The trouble is that, 40 years ago, anyone did."