During one of the most high-profile spy cases in U.S. history, onetime State Department official and accused Communist spy Alger Hiss was convicted of perjury based in part on several rolls of film found inside a pumpkin on a Maryland farm. In 1975, when the film was declassified, one roll was revealed to be completely blank; another contained such mundane information as manuals for military parachutes and fire extinguishers. Hiss claimed until his death in 1996 that the evidence known as the Pumpkin Papers vindicated him, but his claims often fell on deaf ears.

Despite decades of FBI scrutiny, frenzied Red scares, blacklists, loyalty boards, and show trials aimed at ferreting out Communist infiltration, many, perhaps most, of those who acted in the service of the Soviet Union never had a Pumpkin Papers moment. But newly released documents from U.S. and Soviet archives show that hundreds of people, from the famous to the obscure, crossed paths with Soviet intelligence during the pre-World War II years. They include the country's most famous physicist, Robert Oppenheimer, novelist Ernest Hemingway, and civil servants like Hiss. There were journalists, too, like Walter Lippmann, I. F. Stone, and Bernard Redmont, a former correspondent for U.S. News who has been denying spying allegations for more than a half century.

In the two decades since the end of the Cold War, various archives in formerly Communist countries, from Georgia to East Germany, have been opened to historians, who have eagerly pored over their files in the hopes of fitting more pieces into the Cold War's most vexing jigsaw puzzles. (It is an unfortunate irony, some scholars note, that some of the best Cold War documents come from abroad rather than from the United States, where they are still classified.)

A new history of Soviet espionage in the United States during those critical pre-World War II years takes full advantage of a brief peek at one of the crown jewels of Cold War history, the brown and green file folders of the KGB's American Department. Spies: The Rise and Fall of the KGB in America (Yale University Press) was written by a pair of American Cold War scholars, John Haynes and Harvey Klehr, and a former KGB officer and journalist, Alexander Vassiliev.

For a tantalizingly brief two-year period in the early 1990s, Vassiliev was given access to Stalin-era KGB files in order to write about KGB operations. The new book shows how the Soviets went about the business of spying, its failures and successes, and, most interestingly, the names of the Americans from whom the KGB received information.

Since Vassiliev wasn't able to take the originals outside the archive, he filled more than 1,100 notebook pages with the text and marginal notes of thousands of KGB files, often verbatim. Years later, he smuggled the notes out of Russia. Last month, Vassiliev donated the original notebooks to the Library of Congress. The project is not without controversy, partly because researchers have had access only to the notes which Vassiliev, a former Russian spy, took but also because the copies are often the only piece of evidence against those fingered as spies, most of whom are long dead.

But the Vassiliev notebooks are just one piece of the spying puzzle. In 1996, the National Security Agency released voluminous records of the top-secret Venona Project, including many partially decoded Soviet cables detailing spying. Because the cables used code names to shield the identities of KGB sources, they were of limited use to U.S. intelligence. What's significant about the newly released Vassiliev documents is that they contain both the code names from the Venona cables and the actual identities.

A final confirmation? The most famous person who crops up in the new book and accompanying documents is Hiss, who had been convicted of perjury because of the Pumpkin Papers but was never convicted of more serious crimes.

The material in the Vassiliev notebooks corroborates the suspicion that Hiss was a longtime agent of Soviet military intelligence. That echoes the findings of Venona Project analysts, who concluded years ago that the code name "Ales" in the intercepted Soviet cables was "probably Alger Hiss."

The KGB files also corroborate that Julius Rosenberg, who was executed for espionage in 1953 along with his wife, Ethel, was indeed a Soviet agent.

Other Americans are vindicated by Vassiliev's KGB notes. For instance, they say that Robert Oppenheimer continuously refused to help the KGB, much to Moscow's frustration. After a public investigation into his loyalty, Oppenheimer lost his U.S. security clearance. Like many other accused "Red sympathizers," he spent the rest of his life defending his reputation. The Vassiliev documents concur with numerous other sources that show it was other scientists and technicians on the atomic bomb program who helped the Soviets develop a nuclear weapon.

One of the most compelling pieces of Vassiliev's notes is a 1948 memo from Anatoly Gorsky, the chief Soviet spy handler in Washington until 1945. It lists the code names and true identities of members of a spy ring run by Elizabeth Bentley. A private citizen who was a member of the Communist Party of the United States, Bentley triggered one of the most public spy trials in history when she began naming names of all those who had helped her spy for the Soviets in the years before the war.

The Vassiliev notes show that the Bentley ring was one of the most successful that the Soviets ever orchestrated. "The single most disastrous event in the history of Soviet intelligence in America was Elizabeth Bentley's decision to turn herself in to the FBI in 1945 and tell all she knew," Vassiliev and his coauthors conclude in Spies.

Refuting allegations. Bentley ran a network of spies that included, she claimed, a former press officer for the State Department named Bernard Redmont. After Bentley's confession, but before any trial, the FBI began tailing Redmont and his wife.

Based on Bentley's confession, government agents read his mail, tapped his phone, and kept tabs on his job applications, according to declassified FBI reports. One of the jobs for which Redmont, a former marine, applied was as a correspondent with a new publication run by prominent conservative columnist David Lawrence. The G-men erroneously listed the magazine in their surveillance reports as U.S. Reports & World News.

In a trial stemming from the Bentley case, Redmont, then the Paris correspondent for U.S. News, denied being a Communist or a spy. He said that he and Bentley "discussed only material that was available and given to hundreds of other newspaper reporters and agencies and that could have been gotten by listening to the radio any day of the week." But the fact that his name was all over the front pages was enough to shatter his reputation. Lawrence fired Redmont as soon as his testimony hit the papers.

Years later, he found work again in newspapers and then with CBS News, leading to a distinguished career that took him to Boston University, where he served as the dean of the journalism school. Now retired, he lives in Massachusetts.

But the KGB documents offer evidence that Redmont may have been a spy after all, one who operated under the Soviet code name "Mon," according to Vassiliev and his coauthors. Haynes, a historian with the manuscript division of the Library of Congress, says the evidence against Redmont is strong. KGB memos from December 1945 and 1948 reported that Mon had been compromised when Bentley talked to the FBI. "He may have been a minor source, but documentary evidence is that he was a source," the authors write.

But the case against Redmont is anything but closed and, unlike many others named in the book, he is able to refute the charges. What emerges from the Moscow archives and the Venona cables is a picture of two agencies, the FBI and Soviet intelligence, that were both under intense political pressure and inclined to exaggerate their own efficacy. The FBI was largely unable to thwart Soviet spies, was prone to abuses in its hunt for enemies, and often overstated its successes, says Athan Theoharis, a professor at Marquette University and an expert on FBI counterintelligence. Soviet spy handlers, meanwhile, were also under tremendous pressure to produce results and justify, among other things, their expense accounts. They'd sometimes listen to commercial radio news reports or read newspapers, summarize them, and send the results back to Moscow as if they'd gathered top-secret information through their spy networks.

There may be a strikingly benign explanation for the fact that Redmont's name appears on a list in the Moscow archives, says Svetlana Chervonnaya, a scholar and documentary producer in Russia. She suggests that Redmont may have been considered by the KGB as a "journalistic asset," someone used to obtain information and, more important, as an avenue for promoting the Soviet line in the media. The latter was of particular interest as early as the 1930s. "Most often, the journalists were not aware they dealt with intelligence operatives who were undercover as Soviet Embassy press officers or did not deal directly with the Soviets at all," says Chervonnaya. That was the case with Walter Lippmann, the Spies authors conclude. I. F. Stone, meanwhile, actively assisted the KGB, and Ernest Hemingway, according to the files, was given a code name "Argo" but never provided any information.

No one has ever been able to point to any information (secret or otherwise) that Redmont passed to Soviet handlers, nor is there evidence he ever took KGB money. Years of FBI surveillance turned up nothing, and bureau agents repeatedly asked that the investigation into him and his wife be closed. No one ever alleged that he had in any way compromised national security.

Redmont said in an interview last year when the Vassiliev documents surfaced that he "never understood why anyone would name me as a spy. I am not now a spy, and I have never been a spy." And he now says he's dismayed to have the issue dredged up after so many years. "It was a very sad and poisoned period in American history where an allegation was equivalent to a conviction. I'd like to think we've moved beyond that, but maybe we haven't," he says.

Soviet paranoia. The parade of declassified materials raises a larger and perhaps more important question for historians of Cold War spying. Namely, was it worth it? In another new Yale University Press book, Alger Hiss and the Battle for History, journalist Susan Jacoby agrees that Hiss was most likely guilty. Yet that fact is insufficient to justify the McCarthyism and self-destructive Red-baiting that ensued, she writes. The same could be said of the Redmont kerfuffle.

If anything, scholars at a recent Smithsonian conference on Vassiliev's notebooks suggested, KGB reports to Stalin probably reassured the paranoid Soviet leader of the true intent of U.S. foreign policy. Much as mutually assured destruction with nuclear arsenals perversely calmed Cold War nuclear tensions, mutual spying may have reassured policymakers that they truly understood the other side.

Nonetheless, the Soviet Union exhausted considerable efforts to identify and detain suspected agents provocateurs and built a police state on a foundation of denouncers and gulags. The United States, meanwhile, had its own show trials and televised denunciations before the House Un-American Activities Committee and shattered often innocent lives with allegations and innuendo. Even if new evidence suggests that all the smoke was not without fire, McCarthyism remains in the lexicon as the embodiment of politically motivated character assassination. While spy hunts did catch some of the guilty, it is unclear if it was worth the cost to the innocent when nations turned on themselves for crimes both real and imagined.

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