Dark Sun: The Making Of The Hydrogen Bomb

Special Engineering Detachment — the SEDs, the technically skilled enlisted men were called — and was assigned to Group E-5 under explosives expert George Kistiakowsky. At first he worked on high-speed cameras and did not realize that the ultimate goal of the project was developing the atomic bomb. “About a month or two after I was assigned there,” he recalled after the war, “I heard it among the employees.” By October he was machining high- explosive lenses in Group X-1 under Walter Koski, which did flash photographic studies of imploding cylindrical shells. “The group also weighed the advantages and disadvantages of various explosives and explosive arrangements,” notes a technical history of Los Alamos. The theoretician who analyzed Koski's photographs was Klaus Fuchs.

Once Greenglass knew what he was working on, he tried to alert Julius Rosenberg, apparently by telegram. He followed up his telegram with a letter to Ruth on November 4:

I am worried about whether you understand what my telegram is about? I really shouldn't because I know that you are intelligent and will understand. I was happy to hear that you spent a pleasant day with the Rosenbergs. My darling, I most certainly will be glad to be part of the community project that Julius and his friends have in mind. Count me in dear or should I say it has my vote. If it has yours, count us in.

“Community project” was “that business with the Capitol Theater,” Greenglass clarified in 1979, “that time I suspected espionage.” “Friends,” as before, were “the Russians.”

The Greenglasses missed each other. Their first wedding anniversary was November 29; they decided to rendezvous in Albuquerque to celebrate it.

Before Ruth left, she had dinner with the Rosenbergs. “I got invited to Eth's house for supper,” she wrote David on November 15,1944, confirming the occasion, “so I went home with them… I had a very lovely evening at Eth's as you can imagine… We spoke about several hundred things.” Among those several hundred things, Ruth testified later, she and the Rosenbergs discussed espionage and the atomic bomb:

Julius Rosenberg told me that I might have noticed that he and his wife… in recent months had not been attending any Communist Party meetings or any functions that had what he described to be a “Red” tinge to them, and that Ethel… had not been buying the Daily Worker at her usual newsstand… [He] said he always wanted to do more than to be just a member in the Communist Party and that, therefore, he had searched for two years to place himself in contact with a group which I believe he described as a “Russian underground.” In this way… [he] felt that he could do the work that he was slated for… He… wanted to do something directly to help Russia…

Julius… then told me that my husband David was at that time working at the place where the atom bomb was being made…

Ruth knew her husband's work was secret, but she had not known its purpose. “I asked [Julius Rosenberg] how he knew and he said he just knew, his friends told him. He knew about it and he wouldn't go into it any further.” It excited him. “Then he said that it was the biggest thing yet, that it was top secret.” It was more dangerous than any weapon ever used, he added. “He also told me that there were radiation effects from the bomb.”

Having identified the quarry, Rosenberg next offered Ruth his standard rationalization for why two American citizens twenty and twenty-two years old should volunteer for criminal espionage:

He felt it was information that should be shared, that all countries should have it, you know, to their mutual benefit and that Russia was not being given this information and that just on a basis of exchanging mutual scientific information he felt that he was going to do his part to obtain it for them and he asked if I would relay that to David and ask if he would participate.

Ruth Greenglass testified that she objected. “I didn't like the idea.” At that point, in Ruth's recollection, Ethel Rosenberg spoke up in support of the project. “When I stated my reluctance, Ethel felt that this would be something that [David] would want to do, that I should mention it to [him], at least I could deliver the message… She said she felt it would be something he would want to know… She urged me to tell David about it, because she felt that he would be willing to do it.” Whatever Ruth's reluctance, she agreed to carry the Rosenbergs’ message. Julius Rosenberg sweetened the deal with cash. Before Ruth left for Albuquerque, he gave her “about $150 to help pay the expenses of my trip.”

Travel was difficult in wartime and Ruth had trouble getting tickets. She took a chance on a seat opening up out of Chicago, left New York early, hung around the Santa Fe ticket window until a ticket agent took pity on her and made it to Albuquerque on Sunday, November 26, two days early. David joined her at the Franciscan Hotel on Tuesday evening on a three-day pass; they stayed together through the weekend. Besides renewing their marriage and celebrating their anniversary they did some shopping; Ruth noticed after David left that she had “accumulated plenty of junk to take back.”

Ruth waited until late in the vacation to deliver the Rosenbergs’ message. “We went for a walk out on Route 66.” David would testify, “past the… Albuquerque City limits, and not yet to the Rio Grande River, and my wife started the conversation.” Ruth began by telling her husband that he was working on the atomic bomb. “I was very surprised,” he recalled. “David asked me how I knew about that,” Ruth said, “because he had never divulged any information, and I told him that Julius told me.” She described her dinner with the Rosenbergs and their proposal. “She said that my brother-in-law explained that we are at war with Germany and Japan and they are the enemy and that Soviet Russia is fighting the enemy and is therefore entitled to the information.” Ruth also told her husband, in his words, “that she didn't think it was a good idea… and that she didn't want to tell me about it.” “I felt that we had taken something into our hands that we were not equipped to handle,” Ruth explained her misgivings, “[that] we were tampering with things that were beyond our knowledge and understanding…” She asked her husband what he thought about it. Reality was different from vague promises of going into business after the war, David remembered feeling; “you're jumping into cold water.” “At first I was frightened and worried about it and I told… my wife that I wouldn't do it.” But he thought about it overnight, consulting “memories and voices in my mind,” and loyalty won out over caution. “I felt it was the right thing to do… according to my philosophy at the time,” he would testify. “… I started to have doubts almost as soon as I said that I was going to give the information… [But] I had a kind of hero worship there and I did not want my hero to fail, and [by refusing to cooperate] I was doing the wrong thing by him. That is exactly why I did not stop the thing after I had the doubts.” His hero, he said, was Julius Rosenberg. The next morning he told Ruth he was in.

“She asked me for specific things that Julius had asked her to find out from me,” David remembered. “She asked me to tell her about the general layout of the Los Alamos atomic project, the buildings, number of people and stuff like that; also scientists that worked there, and that was the first information I gave her.” Among other names, David remembered mentioning his superior, George Kistiakowsky, as well as Robert Oppenheimer and Niels Bohr.

Rosenberg had asked Ruth to determine the bomb laboratory's situation. Surprisingly, David took her to see it — to see, in her words, “how it was located, whether it was camouflaged, whether you could see it easily. And I remember it now, as I saw it while I was there: it was very high on a hill, the place had been a school for horseback riding — a girls’ school [sic: Los Alamos had been a private boys’ school before the Army requisitioned it]. It couldn't be seen or easily detected until you were almost upon it. And of course it was guarded; there was a guard checking everyone going in and out.”

More train trouble delayed Ruth's travel home. On Monday night she got a coach seat to Chicago. The train broke down in Newton, Kansas, and was late into Kansas City. She was stuck in Chicago until Wednesday; she finally returned to New York on Thursday. A few days later, Julius Rosenberg stopped by her apartment — “alone,” she said. “He was almost always alone.” By then she had written down what David had told her and what she had seen of Los Alamos. She gave her brother-in-law her notes; he told her he would discuss the information further with David when the young machinist came home on furlough.

David Greenglass returned to Los Alamos from his second honeymoon alert to learn more about the novel technology he was helping develop, but he quickly realized that he lacked a frame of reference. “I didn't exactly know what I was looking for,” he testified; “I didn't have a conception of how the bomb was made… ” He began