On April 5, 1951, Judge Kaufman pronounced sentence on Julius Rosenberg, Ethel Rosenberg, and Morton Sobell. At the sentencing, Kaufman announced that he would not ask prosecutor Saypol for his recommendation, and that, after much soul-searching, he had arrived at his decision on his own.

Over the years, from a variety of sources, it is clear that this was not the case. At least a month before the trial began, the Justice Department discussed the usefulness of the death penalty as a device to force Julius to confess. Surely, Kaufman was aware of these discussions.

Also, contrary to Kaufman's contention, he sought advice. He solicited opinions from other federal judges, including Jerome Frank, who would later rule on an appeal from the Rosenbergs. Roy Cohn, who maintained that he had not discussed the possible penalties with Kaufman, states in his "autobiography" that he recommended death for all three defendants.

Irving Saypol was asked by Kaufman for his recommendation, and then told not to make a public pronouncement of it at the sentencing hearing. Saypol recommended death for Julius and Ethel, and thirty years for Morton Sobell. Kaufman instructed Saypol to find out what the Justice Department thought about the matter.

Uncomfortably for Kaufman, the FBI, including not only principal agent Lamphere but the Director, J. Edgar Hoover as well, recommended that Ethel not be given the death penalty. Hoover's biographer suggests that the Director now regretted the strategy of using Ethel as a "lever" to induce Julius to confess, and thought that it would be terrible public relations to execute a mother of two young children. However, Hoover did think that Sobell should be given the death penalty along with Julius.

Kaufman took Saypol's recommendation. Before pronouncing sentence, Emanuel Bloch appealed for a sentence less than the death penalty, arguing that the offenses had taken place when Russia was our ally. Kaufman pointed out that the espionage continued on after the war was over.

The sentences were harsh. Kaufman, in his sentencing Julius and Ethel to death, said:

[Your crime is worse than murder, for you put] into the hands of the Russians the A-bomb years before our best scientists predicted Russia would perfect the bomb has already caused, in my opinion, the Communist aggression in Korea, with the resultant casualties exceeding 50,000 and who knows but what that millions more innocent people may pay the price of your treason. Indeed, by your betrayal, you undoubtedly have altered the course of history to the disadvantage of our country.

Therefore, Julius and Ethel Rosenberg were sentenced to die in the electric chair sometime during the week of May 21, 1951. Morton Sobell received a sentence of thirty years in prison, with the judge's recommendation that he serve the full term.

David Greenglass, whose sentencing had been put off until after the Rosenberg trial, received fifteen years. He had expected five. Considering the severity of the sentences of the three principals in the Rosenberg-Sobell trial, it would have been "unseemly" to sentence Greenglass lightly.

These harsh sentences should be compared to the sentences received by the British spies. As was mentioned, Alan Nunn May received ten years, Klaus Fuchs (whose offense was much more serious than that of the "Rosenberg Ring") received fourteen years. Rebecca West quotes a Russian as saying:

In England, now that the war is over and espionage trials take place in open court, persons detected in espionage on behalf of the Soviet Union are instructed by whichever of our organizations it is which has been using them, to plead guilty and to admit to the police their participation in the particular crime of which they are accused, and nothing more. In the United States such persons are at present instructed to proceed in precisely the opposite way and to deny everything. This is a compliment to England. It is felt that British procedure is so efficient that if a false plea of not guilty is entered, it will be dectected ... and other matters may be stirred up which will extend the scope of the inquiry into the doings of the Communists ... In the United States, where legal proceedings are likely to be prolonged and confused, and all sorts of considerations may prevent the truth from appearing, it is worthwhile putting up a plea of not guilty, no matter how absurd this may be in view of the real facts.

So, the Rosenbergs were in the wrong place, the wrong country, and --- considering the wave of anti-communism and the war in Korea --- the wrong time.