Michael and Robert Meeropol, 80 and 76, have been fighting the brute force of American injustice pretty much all their lives, ever since their parents were given the death penalty in one of the most notorious cases in history.

In 1951 Julius and Ethel Rosenberg were found guilty of conspiracy to commit espionage, specifically passing secrets about the atomic bomb to the Soviet Union. It was the height of the Red Scare, a time many people are now re-examining with the release of Oppenheimer, about the theoretical physicist J Robert Oppenheimer, who was the director of the Los Alamos laboratory.

Robert, left, and Michael are still filing information requests to learn about their parents’ cases.

Christopher Nolan’s film depicts the 1954 security hearing in which the man who developed the atomic bomb had his security clearance revoked, a left-wing but somewhat naive Jewish intellectual brought down by right-wing American paranoia.

The Rosenbergs’ ordeal began with the arrest of Karl Fuchs, a Soviet spy who worked at Los Alamos with Oppenheimer. This led to the arrest of Ethel’s brother, David Greenglass, another Los Alamos worker, and soon after that Julius and then Ethel. Even at the time many Americans were appalled, particularly at the prospect of the execution of Ethel, a 37-year-old mother of two small boys. Roy Cohn — the young chief assistant prosecutor — successfully argued for it, and in June Michael and Robert marked the 70th anniversary of their parents’ deaths in the electric chair at Sing Sing prison in New York.

“I generally spend the day very quietly. In fact, one year Rob called me and asked what I’d done that day and I said, ‘I’ve been thinking about baseball,’ because my grandson had a game that day. But then I realized: ‘Oh, that’s what I was doing the night it happened when I was ten — I was playing baseball,’” Michael, a former economics professor, tells me from his home in upstate New York.

Ethel and Julius Rosenberg, en route to jail after their conviction, March 29, 1951.

He was playing baseball when his parents were killed?

“Yes. There were a lot of reporters, so we were taken away from home for the night, and I remember playing catch with local kids while it got dark.”

As the younger brother, Robert’s memories are hazier: he recalls visiting his parents in prison — in fact, his only memories of them — but is characteristically careful about specifics. “The memory of a particular event from when you were six is suspect. But Michael and I have come to deal with it very quietly,” Robert, a retired lawyer, says from his home in Massachusetts.

“I generally spend the day very quietly.”

They have dealt with their emotions privately, but Michael and Robert have long been public campaigners for justice. In 1990 Robert started the Rosenberg Fund for Children, supporting children whose parents are targeted because of their political activism. In 1975 the brothers sued the FBI and CIA to reveal the secret documents that they believed would prove their parents’ innocence. In fact, their father, an engineer-inspector, was passing on military secrets to the KGB — but not about the atomic bomb, which was the crucial allegation against him. “I realize I would never have done what Julius did, when I had small kids,” Robert says with some emotion. But he quickly tempers his criticism of his father. “I grew up in the 1960s and in prosperity, whereas they were children of the Depression and they saw the Second World War, so I’m not going to say the choices I made were the ones they should have made.”

Robert and Michael, outside the White House, protest their parents’ arrest, June 1953.

Michael is more bullishly defensive, focusing on the US government’s mischaracterizations of Julius.

Ethel, however, was definitely not a spy. Cohn encouraged Greenglass to betray his sister and lie about her involvement in the hope of scaring Julius into naming names. It didn’t work. After she was killed, the deputy attorney-general William Rogers said: “She called our bluff.”

Aftershocks from the Rosenberg case ripple through the present day, which is why it still fascinates.

This summer, alongside the release of Oppenheimer, the American playwright John Jiler is bringing his play The Rosenberg/Strange Fruit Project to the Edinburgh Festival after a run in the US. “The story has an eternal relevance. The shadow of the extreme right seems to be lengthening over us. Plus there’s the misogyny. By no reasonable argument did Ethel Rosenberg deserve to die,” Jiler says.

Senator Joseph McCarthy, left, and Roy Cohn, his chief counsel, during a televised Senate-subcommittee meeting on Communist activity, 1954.

The play focuses on Robert, but Jiler is equally fascinated with both of the Meeropols, describing them as “a testament to the resilience of the human spirit”.

“By no reasonable argument did Ethel Rosenberg deserve to die.”

He is not the first writer to be drawn to the brothers; EL Doctorow’s 1971 novel The Book of Daniel imagines what it would feel like to be the child of the Rosenbergs. Robert describes these fictional takes on their lives as “potentially exploitative”, while Michael simply says: “Fiction is fiction.”

In one of her letters from prison, Ethel wrote: “We are the first victims of American fascism.” Have things in America have improved since then?

Michael is forthright. “I would say that it’s worse.” Applications to the Rosenberg Fund for Children have rocketed, which Robert puts down to growing police violence against protesters.

Playwright and actor John Jiler, left, and clarinetist Lee Odom in a 2022 production of The Rosenberg/Strange Fruit Project, a play about Robert’s life.

Before Cohn’s death in 1986 he mentored none other than Donald Trump. When Trump won the 2016 election, it felt to Michael and Robert as if Cohn had won again. After Joe Biden was elected, they were hopeful he might look favorably on their campaign to have their mother exonerated, but then Russia invaded Ukraine.

“My parents thought they were fighting fascism [by being pro-Russia Communists]. But now I would say fascist elements are pretty much in control of the Russian federation and Russia is the enemy again, so it becomes politically difficult.” Robert adds with a wry smile: “Cohn was Trump’s mentor, then Putin helps Trump be elected, and then Putin’s action prevents us from restarting the exonerate Ethel campaign. You couldn’t make this stuff up.”

After their parents’ deaths Michael and Robert were adopted by Abel and Anne Meeropol. Abel wrote the poem Strange Fruit, which, when recorded by Billie Holiday, became a civil rights anthem, and the boys grew up going on marches.

Recently Michael and Robert filed another request for information, having learned that there are more documents related to their mother’s case. Are they ever tempted to just live a quiet life rather than on the political front lines?

“One of Rob’s favorite lines from way back when was: ‘I don’t know how to be anybody but me,’” Michael says. “And that always resonated with me because, you know, we are who we are.”

The Rosenberg/Strange Fruit Project is on at the Edinburgh Festival Fringe through August 27

Hadley Freeman is a writer for The Sunday Times