Atom Spies - Klaus Fuchs and Others
The atomic bomb was developed in the USA during the tense atmosphere of WWII. The discovery of fission of uranium in 1938 had made the nations aware of the feasibility of an explosive device of immense power. The need to find what other countries are doing was paramount.
USA through their ALSOS spy programme could ascertain that the German atom bomb programme was not making much progress. In fact a decision was made by Hitler that the bomb will take too long for it to be useful for the ongoing war.
The main spy ring was operated by the Soviet Union who were a friendly power during the war. The KGB operated a sophisticated espionage system largely through their embassies. In fact, USA turned a blind eye to most of the spying activity during the war.
The most notable of the spies was Klaus Fuchs and in the following some details are given about him.