David Greenglass: Atomic Spy in the Manhattan Project

by Martha Hutchens

Sign at Los Alamos, NM
Image by Martha Hutchens

“If these two die, I shall live the rest of my life with a very dark shadow on my conscience.” David Greenglass

There were three known spies in Los Alamos during the Manhattan Project. (There is a code name for one more, but many believe he was made up by the Russians as a disinformation campaign.) The last two months, I discussed the most famous, Klaus Fuchs. Today, I will tell you about David Greenglass.

David was born in New York City on March 2, 1922. He had an older half-brother, and two older siblings, of which his sister Ethel would be the most important to the course of his life. His father ran a machine shop, and David enjoyed reading the technical manuals there from a young age.

Komsomol Membership Card
Image by Mankukuku via Deposit Photos

Ethel became involved in labor disputes and joined the Young Communist League. She met Julius Rosenberg there, and they married in 1939. Ethel and Julius were true believers and active in the communist cause. They recruited David to joint them.

David never believed in communism enough “keep delivering papers on a Sunday morning,” one of his early assignments. He attended meetings infrequently and was delinquent in paying his dues. He dropped out of the league after a year or two.

David entered college to study engineering, but spent so much time with the neighbor girl, Ruth Printz that he failed his classes and was asked to withdraw. He worked at several machinist jobs before finally taking a job at Peerless Laboratories. Ruth and David married in November of 1942. He was drafted in April of 1943. He was first assigned to the Army Ordnance Base at Aberdeen, Maryland.

Image by Stockasso via Deposit Photos

On one of his trips back to New York to visit Ruth, he attended the movies with Ruth, Ethel and Julius. Julius informed him that he had volunteered to spy for the Soviets. While the particulars of his introduction vary, it seems clear that he was already spying by late 1942.

David and Ruth discussed their communist leanings in the letters that they exchanged. While nothing in the letters was censored, they would later be used as evidence against him. While David was in the army, Ruth became more active in Communism, finally becoming president of a chapter of the Young Communist League.

David was assigned to various places stateside while he worked in the army as a machinist. Occasionally, Ruth managed to join him in the place he was assigned. On June 30, 1944, six men were assigned by name to the Special Engineer Detachment, Manhattan District, in Oak Ridge Tennessee. One of these men was AWOL, and was replaced with David Greenglass.

In letters, Ruth pressed him about this assignment. In one letter, she mentioned that Julius told her what David must be working on.

After only a week at Oak Ridge, David Greenglass was transferred to Los Alamos.

Lamy Train Station where many
Los Alamos scientists (including David Greenglass)
 left the train for buses to Santa Fe
Image by Martha Hutchens

David arrived at Los Alamos at the same time when the Soviets lost contact with Klaus Fuchs. At this time, Julius was actively spying for the Soviets. He mentioned that his brother-in-law was working in a facility in New Mexico. Leading Soviet agents in New York sought permission to recruit Ruth and, through her, David. That permission was granted on October 3, 1944.

David and Ruth planned to meet in Albuquerque in early December of 1944. On December 2, Ruth delivered a message from Julius to David, asking him to give information to the Soviets. Ruth claimed not to be happy with the idea, but left the decision to David. David answered the general questions sent by Julius, such as the number of people employed there and the number of buildings in use.

Two days later, David returned to Los Alamos to begin his career as a spy.

On January 1, 1945, David arrived in New York City to visit Ruth. He transmitted information that Los Alamos was working on two types of atomic bombs. The Soviets had already received this information from Ted Hall, but they did not trust it. Eventually, it would be confirmed by Klaus Fuchs.

Image by Wirestock via Deposit Photos

In February, Ruth moved to Albuquerque, and David was allowed frequent passes to visit her. During one of these passes, Harry Gold met with David Greenglass.

Harry Gold was Klaus Fuchs’ Soviet contact. His meeting with a second source was a violation of tradecraft, because if he knew more than one spy, he could reveal more than one spy. Eventually, this is exactly what would happen.

When Klaus Fuchs’ activities were revealed, he was given the choice of revealing his comrades or being executed. He revealed the only person he knew, Harry Gold. When Harry Gold was given the same choice, he revealed the only other operatives he knew, David and Ruth Greenglass. In 1950, David was detained. He confessed, and implicated his sister and brother-in-law, Julius and Ethel Rosenberg. They never confessed, and refused to implicate anyone.

Image by zeferli via Deposit Photos

The Rosenbergs were tried in 1951. David agreed to testify in an agreement to prevent Ruth from being tried. David was sentenced to 15 years, of which he served nine and a half. He wrote to the president requesting clemency for the Rosenbergs, but they were executed in 1953. The quote at the beginning of this post comes from that letter.

David Greenglass is an ambiguous character. He never seemed completely committed to the communist cause. He received little financial incentive for his espionage. His motives for his actions seem contradictory at best. Of the three known spies in Los Alamos during World War II, I find him the most confusing.