On New Year’s Eve, 1936, Ethel Greenglass, a young woman who was known in some New York circles for her lovely soprano voice, was invited to perform at a benefit for the International Seamen’s Union. Ordinarily, she was a confident singer; she had, after all, recently won a place in a prestigious amateur chorus, the Schola Cantorum, which performed at Carnegie Hall. But on this occasion, she was nervous, overcoming her anxiety only thanks to the ministrations of an 18-year-old engineering student called Julius Rosenberg. Introduced to her by a friend, Julius suggested that they find an anteroom in which she could rehearse for him until it was time for her to go on.
Once it was all over, Julius walked Ethel home and thereafter the two were inseparable. “I have loved her since that night,” he would say later. “And always when I hear her sing it is like the first time and I know that they can never part us – nothing will.” They married in 1939, in a Lower East Side Orthodox synagogue (though as active communists, religion was of little importance to them) and their relationship, happy and supportive, would end only in June 1953 when, having been convicted of conspiracy to commit espionage, they were sent to the electric chair. Could Julius have saved Ethel’s life? Yes. A confession, on his part, would have done it. But for all that she insisted on her innocence, this was not what she wanted. As she wrote to her lawyer, four months before the sentence was carried out: “I could retch with horror and revulsion for these unctuous saviours, these odious swine [who] are actually proposing to erect a terrifying sepulchre in which I shall live without living and die without dying.”
Anne Sebba’s new biography of Ethel Rosenberg is the first to be written since the release of the testimony of her brother, David Greenglass, to a grand jury, following his death in 2014 at the age of 92 (in the US, the grand jury is the institution that decides if there is a case to answer). As such, her book reminds us all over again of the terrible fact that she was betrayed by her flesh and blood; that Greenglass, who had passed nuclear secrets to Julius Rosenberg from the Los Alamos laboratory in New Mexico, perjured himself to save his skin and that of his wife. Those expecting it to deliver big new revelations, however, should think again. Sebba accepts that Julius Rosenberg was a spy – how could she do otherwise? Deciphered Soviet cables, in which he is codenamed Liberal, make it clear that he was an agent and she knows, too, that, at best, Ethel, whose politics one friend described as intransigent, tacitly condoned what her husband was up to. But her book is not really about all that, however detailed her account of the Rosenbergs’ sensational trial.
In the course of her narrative, which clings to the reader like ivy, gripping but suffocatingly horrible, too, she looks at the political hysteria that spread through cold war America like wildfire and at the way in which antisemitism and sexism played their pernicious part in what Sylvia Plath would later describe in The Bell Jar as that “queer, sultry summer”; she also delivers, albeit inadvertently, a powerful denunciation of solitary confinement (Ethel spent two years alone in her cell) and of the death penalty. Above all, though, her biography is a feat of empathy. Ethel’s supposed ordinariness is well known: she was poor, drab, gauche. But Sebba sees that she was extraordinary, too, in her way: ravenous for self-improvement and, at the end, bonded to dignity even as fear rose inside her. How she found the strength to stay calm when her two little sons arrived to visit her in the last hours of her life, and afterwards to write to them so beautifully, I shall never know.
This is the worst of it – those poor, orphaned boys – but there’s horror at every turn. It begins early, with a mother, Tessie, who cannot properly love her daughter (Tessie did not even attend Ethel’s funeral). The amateur shrink in me wonders if this was the beginning of her troubles – did communism fill an emotional space, as well as a political one? – and whether it was also part of the reason why her brother came to despise her (he was only following his mother’s example, after all). The prosecution lawyers, the most famous of whom was Donald Trump’s favourite, Roy Cohn, were devils barely in disguise, and the politicians (Truman, Eisenhower) to whom appeals for clemency were made, the worst kinds of cowards, playing to the crowd rather than to their conscience. As unease at the sentence grew in the US and across the world, even Eleanor Roosevelt, an opponent of the death penalty, would not speak out. Ethel’s electrocution at Sing Sing Correctional Facility, Ossining, was botched – they had to give her five jolts before the job was done – and her sons, Michael and Robby, aged 10 and six respectively, heard of their parents’ death on a television news bulletin.
Reading all this, you try to cling to the hopeful things: to the goodness of Anne and Abel Meeropol, the couple who adopted the Rosenbergs’ sons; to the sons themselves, who grew into such sane and educated men. But as compulsive and as captivating as this book is, what it stirs most is dread. Even as I tried not to exonerate the Rosenbergs in my mind, nor to push away thoughts of all the heinous crimes committed by European communist regimes, I was filled with queasiness at the idea of a nation and its public servants moving like this against a housewife and mother; of what state-sanctioned murder really involves. It all happened at such speed. If this story resonates now, it’s for this reason: the sickly haste that seems always to attend moments of great political and moral peril. In the book, there is a famous photograph of the Rosenbergs, kissing in a prison van after their arrest. She still has on her little white gloves. I can hardly bear to look at it – and yet I could stare at it for ever.
• Ethel Rosenberg: A Cold War Tragedy by Anne Sebba is published by Orion (£20). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply