Seventy years on, the case of Ethel and Julius Rosenberg, a nondescript couple from Manhattan’s Lower East Side sentenced to death in the electric chair, still holds a horrid fascination. The Rosenberg story has been explored in books, films and on the stage, Tony Kushner’s play Angels in America (1991) being one notable example. ‘It was queer, sultry summer, the summer they electrocuted the Rosenbergs,’ begins Sylvia Plath’s The Bell Jar. Arthur Miller denied that The Crucible was about the Rosenbergs, but the New York theatre-going public made the connection anyway. On the night of their execution, 19 June 1953, the audience stood up and observed a minute’s silence after the curtain fell.

The death sentences passed on the Rosenbergs prompted appeals for clemency from around the world, and not just from liberal figures such as Einstein and Sartre; Pope Pius XII, though a virulent anti-communist, appealed unsuccessfully to President Truman to spare their lives, and then again to his successor, President Eisenhower. Their executions provoked revulsion. The judicial murder of Ethel Rosenberg, the mother of two young sons, was especially horrific. She is the only woman to be executed in the USA in modern times for a crime other than murder.

Their trial in 1951 was conducted against a background of Cold War hysteria. People were scared. The American public believed that