At the same time, numerous nuclear scientists wanted to share the information with the world scientific community, but this proposal was firmly quashed by the United States government.
Regardless of their specific motivations, each individual played a major role in the way the Cold War unfurled and the current state of nuclear weapons.
Confirmation about espionage work came from the Venona project, which intercepted and decrypted Soviet intelligence reports sent during and after World War II.
[2] The Venona Files corroborated their espionage activities and also revealed others in the network of Soviet spies, including physicist Theodore Hall who also worked at Los Alamos.
[5] According to Vassiliev's notebooks, Fuchs provided the Soviet Union the first information on electromagnetic separation of uranium and the primary explosion needed to start the chain reaction, as well as a complete and detailed technical report with the specifications for both fission bombs.
[2] Before World War II, the theoretical possibility of nuclear fission resulted in intense discussion among leading physicists world-wide.
Soviet scientists such as Igor Kurchatov, L. D. Landau, and Kirill Sinelnikov helped establish the idea of, and prove the existence of, a splittable atom.
Dwarfed by the Manhattan Project conducted by the US during the war, the significance of the Soviet contributions has been rarely understood or credited outside the field of physics.
According to several sources, it was understood on a theoretical level that the atom provided for extremely powerful and novel releases of energy and could possibly be used in the future for military purposes.
[8] At the urging of Albert Einstein and Leo Szilard in their letter of August 2, 1939, the United States – in collaboration with Britain and Canada – recognized the potential significance of an atomic bomb.
Estimates suggest that during the quest to create the atomic bomb, an investment of $2 billion, temporary use of 13,000 tons of silver, and 24,000 skilled workers drove the research and development phase of the project.
The largest Western facility had five hundred scientists working on the project, as well as a team of fifty to derive the equations for the cascade of neutrons required to drive the reaction.
The research and development of methods suitable for doping and separating the highly reactive isotopes needed to create the payload for a nuclear warhead took years and consumed a vast quantity of resources.
Some historians believe that the Soviet Union achieved its great leaps in its atomic program by the espionage information and technical data that Moscow succeeded in obtaining from the Manhattan Project.
[16] The Soviet Union needed spies who had security clearance high enough to have access to classified information at the Manhattan Project and who could understand and interpret what they were stealing.
Another extremely important individual that played a significant role in the Soviet Union's acquisition of atomic secrets was Harry Gold.
He recruited a number of people to work for the Soviet Union, including Julius and Ethel Rosenberg, David Greenglass, and Klaus Fuchs.
Gold's role in this network was to act as a courier, passing along information and money between the Soviet agents in the United States and their handlers in Moscow.
Without atomic spies such as Harry Gold, Julius and Ethel Rosenberg, David Greenglass, and Klaus Fuchs the rate at which the Soviet Union achieved nuclear weaponry would have been impossible.
Espionage helped the Soviet scientists identify which methods worked and prevented their wasting valuable resources on techniques which the development of the American bomb had proven ineffective.
[24] The activities of atomic spies underscored the intense competition between the United States and The Soviet Union for nuclear supremacy during the Cold War.