@ The Rosenbergs were indeed Soviet spies, as was Alger Hiss.
@ Most of those "falsely accused" by the McCarthyites (including the much-maligned Whitacker Chambers) were, in fact, Soviet spies, assets, or sources.
@ US nuclear bomb scientist J Robert Oppenheimer was not just a Soviet asset, feeding them information on the US nuclear program, but went out of his way to arrange for other Soviet spies to be hired for key government agencies.
@ Harry Dexter White, Assistant Secretary of the Treasury and author of the post-war plans for Germany, was a major Soviet asset who provided information to other Soviet spies he had maneuvered into key government jobs. White went to great efforts to cause tension between the US and Japan in the late 30s in a bid to stop the planned Japanese invasion of Siberia.
@ President Harry Truman deliberately covered up evidence of the true extent of Soviet spying out of fear it would cost the Democratic Party the 1952 elections. The authors show that despite claims to the contrary by Democrats, Truman was fully briefed on the Verona Transcripts, a series of intercepted KGB communications from the late 40s which were kept secret until a few years ago. Truman reportedly doubted that the Verona transcripts could have been accurate; it has since been confirmed that they were completely accurate.--Stephen V Cole
How Soviet Intelligence Operations Changed American History, a new book by Jerrold and Leona Schecter, documents that Soviet espionage in the US was even more widespread than believed, and had serious effects on the US. The book rejects, disproves, and destroys the revision theories of the 80s and 90s that Soviet espionage was minor and irrelevant and that most of those accused of spying were in fact innocent. Using newly-declassified US documents and recently-obtained KGB archives, the book shows that: