Atomic spies or atom spies were people in the United States, the United Kingdom, or Canada, who are known to have illicitly given information about nuclear weapons production or design, to the Soviet Union, during World War II and the early Cold War. Exactly what was given, and whether everyone so accused actually gave it, are still matters of some scholarly dispute. In some cases, some of the arrested suspects or government witnesses had given strong testimonies or confessions, which they recanted later or said were fabricated. Their work constitutes the most publicly well-known and well-documented case of nuclear espionage in the history of nuclear weapons. At the same time, numerous nuclear scientists favored sharing classified information with the world scientific community. This proposal was firmly quashed by the U.S. government.
Atomic spies were motivated by a range of factors. For some, ideology (such as a commitment to communism or other socialist models committed to advancing the interests of the Soviet Union) was the primary reason for their spying. Others were motivated by financial gain, while some may have been coerced or blackmailed into spying. The prospect of playing a role in shaping the outcome of the Cold War may also have been appealing to some. Another large motivational factor was being engrained into the history of the world, an/or being remembered as someone who did something "larger than themselves". Regardless of their specific motivations, each individual played a significant role in the way the Cold War unfolded, and the continuing state of nuclear weapons.
