This is a list of people who have been accused of, or confirmed as working for intelligence organizations of the Soviet Union and Soviet-aligned countries against the United States. In some cases accusations are considered well-supported or were otherwise confirmed or admitted, but other cases are controversial or contested.
For more information, see:
[Koval] drastically reduced the amount of time it took for Russia to develop nuclear weapons.
((cite web)): CS1 maint: location (link)
((cite web)): CS1 maint: archived copy as title (link)