Editors’ Note: In October 2021, Mosaic published an essay by the historain Harvey Klehr, titled “The Eternal Return of Ethel Rosenberg,” exploring the famous espionage case. Below, he and Mark Kramer investigate the most recent revelations about the subject.

More than 70 years after being executed in a dramatic cold-war spy case, Ethel Rosenberg was recently back in the news. Last month, her two sons, Michael and Robert Meeropol, obtained a formerly classified memorandum through the Freedom of Information Act and tried to convince an Associated Press (AP) reporter that it was a “smoking gun” demonstrating her innocence. In reality, the document does no such thing. This episode was just the latest attempt by the Meeropols to propagate baseless claims about Ethel Rosenberg’s innocence. It is worth setting the record straight.

In July 1950, Ethel’s husband, Julius, was arrested on suspicion of espionage, and a month later she was also arrested. The two were eventually tried on charges of conspiracy to commit espionage. In the early spring of 1951, they were convicted and sentenced to death, and in June 1953 they were electrocuted at Sing Sing Prison. The death penalty for the two was excessive, but this does not mean they were innocent of the charges brought against them. All the evidence that has emerged from U.S. and former Soviet archives over the past 75 years shows that the conviction was fully justified, even if the punishment was not.

The Rosenbergs left behind two young sons, who took the name Meeropol from the family that adopted them after their parents’ death. For more than six decades, the Meeropols have been doing whatever they can to convince the American public that their parents were actually innocent. They have also repeatedly urged the U.S. government to issue an official exoneration of Ethel.

For many years the Meeropols tried to exculpate both of their parents, but after the release of crucial U.S. and Soviet intelligence documents starting in the mid-1990s, including the so-called Venona decryptions of Soviet intelligence cables, they gradually acknowledged that their father, Julius Rosenberg, was in fact a Soviet spy who had turned over military and technological secrets. They insisted that Julius had been only a “minor” spy and that their mother, Ethel Rosenberg, was innocent of the charges brought against her and was “murdered” by the U.S. government.

The Meeropols’ latest effort along these lines came last month when the website of the Rosenberg Fund for Children, an organization set up by Robert Meeropol in 1990, posted a press release accompanied by a scan of a seven-page handwritten document that had been declassified by the U.S. National Security Agency (NSA), the agency that oversaw the Venona decryption project as part of its general responsibility for signals and communications intelligence. In the press release, the Meeropols claimed that the newly released document shows “the U.S. government knew that Ethel Rosenberg was not a spy long before her trial and execution.” This assertion is utterly devoid of merit. Far from exculpating Ethel, the document reinforces the large body of evidence indicating that she conspired with her husband to commit espionage.

The handwritten document was compiled in August 1950 by Meredith Gardner, the renowned linguist and cryptographer who had been a key figure in the Venona program to decrypt Soviet intelligence communications collected furtively by the U.S. government during World War II. Gardner’s memorandum gives an overview of various U.S. citizens who had been identified as Soviet spies (“key espionage personnel”) through the Venona program.

Among the “key espionage personnel” listed in the document are members of Julius Rosenberg’s spy ring, including Ethel Rosenberg. The portion about Ethel adds nothing to what scholars have long known about her role from other materials released over the past 75 years. In April 1948, the Venona cryptanalysts completed a preliminary translation of a Soviet intelligence message from November 1944 that referred to Julius Rosenberg by his cover name, Liberal, and also mentioned Ethel Rosenberg by her given name. Four months later, in August 1948, Gardner and his colleagues issued a revised translation that added intriguing information about the Russian text of the message.

The November 1944 Soviet intelligence document gives basic information about Ethel, including that she had joined the Communist Party USA (CPUSA) in 1938 and had married Julius in 1939. It confirms that “she knows about her husband’s work,” referring to his espionage. The document also notes that Ethel, “in view of her delicate health, does not work.” The cryptographers added an explanatory note to their revised translation indicating that the noun “work” used in the cable with regard to Julius is rabota, which is the regular Russian word for work. However, in this context, the cryptographers explain, the noun has a “special meaning” of “conspiratorial” work (espionage). They note that the verb “work” used in the message with regard to Ethel is rabotat’, which is the regular Russian verb meaning “to work.” They indicated they were not sure whether the verb carried the same connotation of “conspiratorial” that the noun did in certain contexts, but they surmised that, “probably,” it “sometimes” did.

The revised translation of the Soviet intelligence document thus confirms that Ethel knew about her husband’s espionage and that, because of her precarious health, she was not working as of November 1944. The document may simply mean that she was not actively employed in the labor force at that time, or it could mean that she was not directly engaged in espionage on the same scale as her husband. The document lends itself to either interpretation. The only thing it clearly indicates is that her condition of “not working” was temporary, brought on by health problems.

In the August 1950 document that was released a month ago by the NSA, Gardner’s paragraph about Ethel Rosenberg includes several points from the November 1944 Soviet intelligence message but without citing it verbatim. Instead, Gardner merely summarizes it. His summary says that “due to ill health she did not engage in the work itself,” which is an imprecise paraphrase of what the Soviet intelligence cable actually says. The Soviet document uses a verb, not a noun, when indicating that Ethel “does not work” (which could also be translated as “is not working”), and it uses the present tense, not the past tense.

Gardner’s August 1950 document is thus imprecise in its wording about Ethel. It also contains several errors, at times because in 1950 Gardner had no access to Soviet intelligence messages that had not yet been decrypted. For example, when referring to someone codenamed “Chester,” Gardner describes him as “an as yet unidentified U.S. atomic scientist.” But we now know that “Chester” was actually Bernard Schuster, a CPUSA official who served as a liaison with Julius Rosenberg. Elsewhere, Gardner’s mistakes stemmed from carelessness. At one point, for instance, his memorandum refers to David Greenglass as “a U.S. atomic scientist who is married to Julius Rosenberg’s sister.” David Greenglass was actually a machinist, not a scientist, and he was Ethel’s brother.

Leaving aside the flaws of Gardner’s August 1950 memorandum, his brief comments about Ethel Rosenberg do not change anything in regard to what scholars have known for many years about her involvement in Julius’s spy ring. The Venona re-translation of the November 1944 Soviet intelligence document is ambiguous about the precise level of Ethel’s involvement, but it confirms that she knew about and approved of what her husband was doing to assist the Soviet Union. That document was available to Gardner in August 1950, but other documents that were subsequently released show even more strongly that Ethel was not just a passive observer of her husband’s espionage activity. On the contrary, she played an active role.

A Soviet intelligence message of September 1944, which was not decrypted until 1975, reported that both Julius and Ethel had urged Soviet intelligence officials to contact Ruth Greenglass (Ethel’s sister-in-law) about setting up a safe house in New Mexico. The Rosenbergs, the message noted, “recommend [Ruth] as an intelligent and clever girl.” They were confident that Ruth would be a valuable conduit to her husband, David Greenglass (Ethel’s brother), who had been assigned to work at Los Alamos in New Mexico on the Manhattan Project, the U.S. government’s highly classified wartime program to build nuclear weapons.

At the criminal trial of the Rosenbergs in 1951, Ruth testified that she had met with Julius and Ethel at their apartment in New York in November 1944, just before she left to visit her husband in New Mexico. During this meeting, both Julius and Ethel urged Ruth to persuade David Greenglass to supply information about the development of the nuclear bomb—a point David confirmed in his own testimony at the trial. After being recruited by Julius with Ethel’s help, David smuggled extremely sensitive information to intermediaries who transferred it to Soviet foreign-intelligence personnel.

Ethel’s active support for Julius’s spy ring, including her crucial role in the recruitment of David Greenglass, is confirmed in transcriptions of documents from the former Soviet foreign-intelligence archive that were brought out of Russia in 2004 by Alexander Vassiliev, an ex-KGB officer. One of the Soviet cables transcribed by Vassiliev, which was sent to Moscow in early December 1944, recounts the meeting Ruth had with Ethel and Julius in November 1944 before contacting David. According to the document, Julius was pleased to learn that Ruth believed “it would be a privilege” to help the Soviet Union. When “Ethel mentioned David, she [Ruth] assured us she felt that this was also David’s understanding,” i.e., that David shared Ruth’s admiration for the USSR and would assist. After Julius gave Ruth a list of questions to ask David and warned her never to write anything down, “Ethel intervened here to stress the need for the utmost care and caution in informing David about the work in which Julius was engaged.” Then, “at this point we asked Ruth to repeat our instructions, which she did satisfactorily.”

The documents transcribed by Vassiliev also show that Ethel suggested other people Julius could recruit to turn over secret information. None of this means that Ethel was a spy on the same level as her husband, but the charge brought against her was not espionage per se. She was accused of conspiring to commit espionage. The incriminating evidence in the Venona decryptions and in the Vassiliev notebooks, which was not available to Gardner in August 1950 or to the prosecutors at the Rosenbergs’ trial in 1951, leaves no doubt that she did conspire with her husband to help the Soviet Union, even if she did not take as direct a part as Julius did in the spying itself. She was guilty as charged, and nothing in the August 1950 memorandum changes that verdict.

This brings us to the AP article by Eric Tucker on September 10, which was prompted by the Rosenberg Fund for Children’s attempt to put an exculpatory spin on Gardner’s memorandum, depicting it as “smoking gun.” Tucker reported that the Meeropols “are urging President Joe Biden to issue a formal proclamation saying [Ethel] was wrongly convicted and executed.” The AP article, which was widely republished, does not fully endorse the Meeropols’ interpretation, and indeed Tucker, to his credit, interviewed both of us and included our brief comments indicating that the Meeropols’ assertions were spurious and ignored abundant evidence that Ethel had conspired to commit espionage. Nonetheless, the article gives the final word to the Meeropols, who insist that their mother “had no role in recruiting spies or assisting her husband’s espionage.” Moreover, the AP article might lead readers to think that the document adds significant new information to the historical record.

Unfortunately, the AP was deceived. The memorandum adds no new information. Far from being “a smoking gun” establishing Ethel’s innocence, the document warrants no change at all in the historical record. The Meeropols are justified in arguing that their parents should not have been executed, but even on this issue they play fast and loose with the historical record. It is clear that the main reason Ethel was indicted was to put pressure on Julius to confess and name other members of his spy ring who had not yet been identified as well as to provide greater evidence that could be used against those who were already known. Neither of the Rosenbergs would have been put to death if they had agreed to cooperate even minimally.

The problem, however, was that the Rosenbergs were so fanatically committed to the Soviet Union that they were willing to become martyrs. Their devotion to Joseph Stalin outweighed their attachment to their own young sons. They refused to acknowledge anything they had done or to name other participants in the spy ring. Instead, they persisted in their false claims of being innocent. Julius knew that he could have bargained to have the charges against Ethel dismissed, but he decided he must maintain the façade of their innocence. Ethel embraced the same position, choosing loyalty to Soviet Communism over the well-being of her own children, who were left as orphans.

It is sad that, after so many years, the Meeropols are still claiming that their mother was innocent of the charges brought against her. The evidence is overwhelming that both Ethel and Julius conspired to commit espionage. It is long past time for the Meeropols to acknowledge the truth about their mother, just as they earlier did (albeit halfheartedly) about their father. At the very least, journalists should stop taking the Meeropols’ claims seriously. Julius and Ethel Rosenberg were the authors of their own destruction.