Nuclear espionage

Nuclear espionage is the purposeful giving of state secrets regarding nuclear weapons to other states without authorization (espionage). During the history of nuclear weapons there have been many cases of known nuclear espionage, and also many cases of suspected or alleged espionage. Because nuclear weapons are generally considered the most important of state secrets, all nations with nuclear weapons have strict restrictions against the giving of information relating to nuclear weapon design, stockpiles, delivery systems, and deployment. States are also limited in their making public of weapons information by non-proliferation agreements.

During the Manhattan Project, the joint effort during World War II by the United States, the United Kingdom, and Canada to create the first nuclear weapons, there were many instances of nuclear espionage in which project scientists or technicians channeled information about bomb development and design to the Soviet Union. These people are often referred to as the Atomic Spies, and their work continued into the early Cold War. Because most of these cases became well known in the context of the anti-Communist 1950s, there has been long-standing dispute over the exact details of these cases, though some of this was settled with the making public of the Venona project transcripts, which were intercepted and decrypted messages between Soviet agents and the Soviet government. Some issues remain unsettled, however.

The most prominent of these included:

Whether the espionage information significantly aided the speed of the Soviet atomic bomb project is also disputed. While some of the information given, such as the highly technical theoretical information given by Klaus Fuchs, would be thought to have certainly aided in developing a nuclear weapon, the manner in which the heads of the Soviet bomb project, Igor Kurchatov and Lavrenty Beria, actually used the information has led later scholars to doubt it having had a role in increasing the speed of development. According to this account, Kurchatov and Beria used the information primarily as a "check" against their own scientists' work, and did not liberally share the information with them, distrusting both their own scientists as well as the espionage information. Later scholarship has also shown that the decisive force in early Soviet development was not problems in weapons design, but, as in the Manhattan Project, the difficulty in procuring fissile materials, especially as the Soviet Union had no uranium deposits known when it began its program (unlike the United States).

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