Julius and Ethel Rosenberg were American citizens who spied on behalf of the Soviet Union and were tried, convicted, and executed by the federal government of the United States. They provided top-secret information about radar, sonar, and jet propulsion engines and were accused of transmitting valuable nuclear weapon designs; at that time the United States was the only country in the world with nuclear weapons.
Other convicted co-conspirators were sentenced to prison, including Ethel’s brother, David Greenglass (who had made a plea agreement), Harry Gold, and Morton Sobell. Klaus Fuchs, a German scientist working in Los Alamos, was convicted in the United Kingdom.
For decades, the Rosenbergs’ sons Michael and Robert Meeropol, and many other defenders maintained that Julius and Ethel were innocent of spying on their country and were victims of Cold War paranoia.
After the fall of the Soviet Union, much information concerning them was declassified, including a trove of decoded Soviet cables, code-named VENONA, which detailed Julius’s role as a courier and recruiter for the Soviets and Ethel’s role as an accessory.
Their sons’ current position is that Julius was legally guilty of the conspiracy charge, though not of atomic spying, while Ethel was only generally aware of his activities. The children say that their father did not deserve the death penalty and that their mother was wrongly convicted. They continue to campaign for Ethel to be posthumously and legally exonerated.
In 2014, five historians who had published works based on the Rosenberg case wrote that newly available Soviet documents show that Ethel Rosenberg hid money and espionage paraphernalia for Julius, served as an intermediary for communications with his Soviet intelligence contacts, relayed her personal evaluation of individuals whom Julius considered recruiting, and was present at meetings with his sources. They support the assertion that Ethel persuaded her sister-in-law Ruth Greenglass to travel to New Mexico to recruit her brother David Greenglass as a spy.
The Rosenbergs were executed on June 19th, 1953. They were the only spies executed during the Cold War.