To take one example, it was an article of faith on the Left for many years that the Rosenbergs were railroaded to the electric chair. And likewise, that Alger Hiss was the victim of a smear campaign by the despicable turncoat Whittaker Chambers. The fact that the Hiss case gave legs to Richard Nixon's early political career is only proof positive that the bottom-feeders of the Far Right have no shame, and are happy to use the basest of lies to promote a culture of fear.
Slight cognitive dissonance, here. What gets lost in the shuffle is that Stalin had in fact mounted an enormous clandestine espionage operation inside the United States in the postwar years. Not that McCarthy made a dent in it.
Which brings us to THE HAUNTED WOOD. In 1995, the FBI began to release the declassified transcripts of the Venona intercepts. Venona was a U.S. counterintelligence program that decrypted cable traffic, specifically Soviet agents reporting back to Moscow. The authors of THE HAUNTED WOOD were given access to KGB archives, and cross-collateralized with Venona, they reconstruct a secret world.
There's an obvious question of provenance. To what degree are the KGB documents---or the FBI documents, for that matter---redacted, or sanitized, or doctored? No security service wittingly gives up material that makes them look bad. The answer seems to be that when both versions of the traffic are available---e.g., the original Russian in Moscow's archive, and the FBI translations---the content matches, with only minor differences such as wording, small errors in vocabulary or grammar that would naturally creep in. A non-native Russian speaker (like this writer, for instance) is bound to make some mistakes. In other words, the resulting analysis is trustworthy. The authors haven't been led down the garden path.
THE HAUNTED WOOD makes a hash of the apologists' case. Alger Hiss, for one, was alomst certainly recruited by GRU, Soviet military intelligence, in the 1930's. And the Russians, of course, found other sympathizers among the anti-Fascist Left, particularly after the outbreak of the Spanish Civil War. You could ascribe this to idealism, or naivete, or a thirst for social justice. There were a lot of people on the Left, in the '30's, who saw the rise of Hitler as the handwriting on the wall, nor were they far wrong. It took a willing blindness, though, to see Stalin as a champion of the oppressed, and as time passed, many of these former willing acolytes fell away from the faith. After the arrest of the Rosenbergs, the Moscow intelligence apparat discarded well-intentioned Old Lefties and turned to pros. Rudolph Abel established a spy network out of Brooklyn that lasted nine years before the FBI rolled him up. Soviet illegals, working under deep cover, weren't a fabrication of J. Edgar Hoover's fevered reptile brain.
None of this is meant to be an alibi for malignant windbags like McCarthy, or the moral cowardice of his enablers. It's widely accepted that the Red-hunters never exposed a single agent of Communist influence. It was all smoke and mirrors. What they did do was create an abiding climate of mistrust, and enshrine the habit of betrayal. It's not a stretch to say that the hearings themselves, with their odor of Stalin's purge trials, the posturing, the parade of friendly witnesses, the public disgrace of others, and the blacklist, the fruit of a corrupt bargain, did more to damage the American political fabric than any number of actual enemy subversives could have hoped for. It poisoned the well for a generation.
The war in the shadows went on. A long stalemate, between two adversaries who each recognized a genuine threat in the other, and found, it seems, their mirror image. This is not in any way to suggest a moral equivalency, but there's a lesson to be taken from the Cold War. We were looking into the past, and trying to see the future through the wrong end of the telescope.