A case could be made that the answer to both categories is Julius Rosenberg. As a spy for the Soviet Union he lasted only a short while and accomplished little of value. But as a martyr of the left who gladly died for his beliefs (he and his wife could have saved themselves by giving the authorities a full confession) he probably did more to legitimize the idea of virtuous treason than any American spy except that other hapless revolutionary Nathan Hale.
An authoritative new book based on KGB archives, The Haunted Wood by Allen Weinstein and Alexander Vassiliev, leaves no doubt whatsoever that Julius—though not his fervently supportive but unrecruited wife, Ethel—was a secret agent of Soviet intelligence from 1941 until his arrest in 1950. Julius (NKGB code name Antenna, later changed to Liberal) virtually recruited himself, volunteering to spy in the wartime factory in which he worked as an engineer. He was already running a four-person espionage cell of fellow engineers for the Communist Party of the United States when he came under the discipline of the Soviet intelligence service.
Julius’s eagerness to help the Soviets knew no bounds. He sought out targets on his own and apparently was unable to stop spying even after he was compromised and his handlers ordered him to cease and desist for his own sake and that of other far more valuable agents he might compromise. A long-time member of the party, Julius was the quintessential revolutionarybeliever, and both he and his wife were motivated by what amounted to religious passion. There were many others like them in the United States during the Stalin era. The Haunted Wood quotes plaintive dispatches from Soviet spymasters of the period claiming to be overwhelmed by volunteers from the American left. Most of these eager amateurs were turned away because Moscow simply didn’t have enough case officers to handle them all.
Julius Rosenberg’s only notable contribution to ENORMOZ, the Russian operation to steal the secrets of the atomic bomb from the United States and Great Britain, was the recruitment in 1944 of his brother-inlaw, David Greenglass, a machinist in the Manhattan Project laboratory at Los Alamos, New Mexico. Greenglass provided Soviet intelligence with marginally useful information on personnel and with diagrams of A-bomb components.
After his arrest, in an apparent effort to protect his ailing wife, who had acted as his courier, Greenglass denounced the Rosenbergs, among others. His trial testimony resulted in a fifteen-year sentence for himself and the death penalty for Julius and Ethel. On June 19, 1953, the Rosenbergs were executed, a punishment so disproportionate to their meager service to the international Communist conspiracy that it guaranteed their place in history and in the folklore of left and right alike as the most overrated spies of all time.
The most underrated spy who ever worked against the United States must, by definition, be one who was never caught. My nomination goes to the asset inside the Manhattan Project who made it possible for the secrets of the bomb to fall into the hands of Soviet spies. Not only has this supremely imaginative and valuable asset never been identified, but his existence has never been proved, and if he did exist, he may never even have been formally recruited. Now that’s trade-craft.