The Rosenberg’s swore an loyalty oath to the Soviet Union. This oath required active participation in the effort of a violent overthrow of the US. The Rosenberg’s not only ran a spy network for the Soviet Union , they delivered top secret information which enabled the Soviet Union to successfully build a hydrogen bomb.
In 1986, when the Soviet Union “ran out of other people’s money” historians at the Kremlin released old Soviet files documenting the details of the Rosenberg spy network. Read about it in a book called “the venona project.”
Venona documents unmistakably identified Julius Rosenberg as the head of a Soviet spy ring and David Greenglass, his brother-in-law, as a Soviet source at the secret atomic bomb facility at Los Alamos, New Mexico.
https://www.nytimes.com/books/first/h/haynes-venona.html
Many people investigated by McCarthy fled to the slave prison of East Germany, a place like today’s North Korea from which ordinary people risked their lives to escape. If someone fled to East Germany during the cold war, they were like someone fleeing to North Korea today . . . assuredly spies.
