The Manhattan Project

Lee DuBridge's Interview - Part 2

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Lee DuBridge is a prominent American physicist whose work at Caltech, Rochester, and MIT and the Atomic Energy Commission led to interactions with J. Robert Oppenheimer. In this interview, he discusses how the AEC felt about testing the hydrogen bomb in context of the nuclear arms race, explaining why many members of the AEC’s General Advisory Committee were initially against moving ahead with a crash program on the hydrogen bomb. He also explains the confusion over using nuclear weapons tactically versus strategically. DuBridge recalls his efforts to support Oppenheimer during Oppie’s security hearing. Most notably, he remarks that as early as a year before the charges were brought against Oppenheimer, people were aware of trouble brewing for Oppie. DuBridge also remembers a visit he made to NATO headquarters with Oppenheimer, and how warmly Oppie was welcomed.
Manhattan Project Location(s): 
Date of Interview: 
March 30, 1983
Location of the Interview: 

Lee DuBridge: So, yeah, we thought it was an exciting time to have the AEC [Atomic Energy Commission]. We knew, of course, that they were going ahead with the weapon development, but also they were going to support Brookhaven and other research centers around the country. So, no, I think those of us who were not imminently in the Manhattan District, but aware of it, were quite excited about getting in and finding out more about really what was going on and what the new possibilities were, both in physics and in weapon technology.

No, I felt highly honored to be chosen a member of the [General Advisory Committee of the AEC]—especially since it was such a marvelous group of people. You could not help but enjoy associating with that group of people. You know who all they were, [Glenn] Seaborg, [Enrico] Fermi, [James B.] Conant, [Isidor I.] Rabi, and Oppie.

Martin Sherwin: John Manley was Secretary?

DuBridge: Yes, uh-huh, yeah.

Sherwin: Is it true that the meetings were tape recorded?

DuBridge: No.

Sherwin: It’s not?

DuBridge: No.

Sherwin: Somebody had said that they were recorded, but then the tapes were destroyed.

DuBridge: I do not remember any tape recording.

Sherwin: Did you take notes?

DuBridge: Manley took notes and wrote up the minutes. No, they were much too informal for any tape recording thing. It was around the table talk, back and forth. Tapes would have been difficult to disentangle, I am sure. But when we came to a decision, Oppie would either write out, or get somebody else to, or maybe get a committee to go aside and say, “Would you summarize for a recommendation, and so on, and we will write it out, and we will go over it, and agree on it, amend it, and agree on it.” 

We often spent a good old time on drafting just what we wanted to say to the AEC in response to any question that they had asked. Of course, we were briefed at great length by various people that are having to do with AEC affairs. We were briefed often by the Los Alamos people as to what they were doing, and how things were going, and what their ideas were, and what experiments they had done, what new ideas they had had, and all of the rest of it. They were fascinating, fascinating meetings.

Sherwin: Were you privy to the sort of central issues related to the relationship between nuclear weapons and defense policy and things like that? For example, what I mean is that recently the numbers of atomic components and bombs was declassified. The numbers are that in 1945—this is probably after Hiroshima and Nagasaki—the numbers were that there were two.

DuBridge: There were two ready to go after Hiroshima and Nagasaki. As a matter of fact—Bob Bacher maybe told you—he had one already packed up to ship out.

Sherwin: Yes, by the 21st, or something like that.

DuBridge: Something like that. Then at the last moment, they said, “Hold the shipment,” because already the Japanese had indicated they were going to surrender. But the third one was essentially packed up ready to go.

Sherwin: Then I guess another one was produced?

DuBridge: Yeah, there was another one coming along, yeah.

Sherwin: Then for ’46, the number is nine. For ’47, the number is, I think, thirteen. I could be wrong, because that sounds small. In ’48, it is fifty. Then it goes up considerably from there.

DuBridge: Yeah.

Sherwin: I have also either read or have been told—at this point I would have to look through a lot of my stuff to know for sure—it was Oppenheimer’s view that the way the military came to its requirements, that is, how many nuclear weapons it would need. He would find out from [General Leslie] Groves how many could be produced. Then he would say, “We need—“

DuBridge: “That is just the number we need.”

Sherwin: “That is the number we need.” Now, in other words I am telling you this to give you a sense of sort of what I know, and what my sense is about what is going on at this time. It is clearly a moment in time of, people do not know exactly what to do with these things. Certain people have hopes of international control. The Russians are not cooperating, to put it euphemistically. There are a lot of cross-currents in the military. What we know today did not exist then. Everything is in the process of becoming, but certainly not in, the framework of some grand scheme or grand plan. 

One of the things that I would like to do if it is possible, again, from the view of the scientific community in the GAC and whatever Oppenheimer had to do with this, is to try to explain with some more clarity than we have now sort of how the structure of nuclear defense, et cetera, emerges.

DuBridge: That is a little tough.

Sherwin: What can you do with that?

DuBridge: You mentioned that the military would ask Groves how many weapons could be made, and they said, “That is just what we need.” It was not quite that bald. You see, there were military liaison people in the AEC office all of the time. They were in touch with everything that was going on. Actually, part of their job was to get more of these weapons built, and to clear the way, to get more plutonium, and so on. It was my feeling that there was a very cordial back and forth relationship between the military people and their superiors in the Pentagon.

Sherwin: Do you have the names of the military people? Do you remember any of them?

DuBridge: Oh, golly, if you mention them I would.

Sherwin: They do not appear in the minutes.

DuBridge: They do not? Bacher could tell you. I am sure he remembers, or his records. I do not have any papers here. But there was one, quite prominent, who I just ran into last summer again after I had not seen him for years. I cannot remember his name. I think the top military liaison man with the AEC at the time, or one of them.

Sherwin: A colonel at the time? A lieutenant colonel?

DuBridge: Probably, yes, colonel. They briefed the GAC on their views on what was needed and so on. They knew it was no use saying, “We have got to have 500 of these things,” when they knew they could not get more than twenty, or whatever it was. They kept in touch with what was going on and what the possibilities were. I think they always wanted more, but they knew there was no use making a big fuss about overreaching and asking for the impossible. They kept in touch and adjusted their plans to the developing technology and production schedules.

I know that there was a great deal of discussion about targets in the Soviet Union, and how many it would take to knock out the major industrial centers or whatnot and so on. Of course, at that time, we thought fifty would just about wipe out the essential things in the Soviet Union. And that is true.

Sherwin: Are you sure about that number?

DuBridge: No, I am just giving it as an example.

Sherwin: Yeah, okay.

DuBridge: Yeah, the number changed. The number changed. I think we sometimes used to sort of smile about this, that they always could seem to find targets for whatever number they thought they could get in the next year or two. They adjusted their target goals to the production goals in a continual back and forth arrangement. 

Oppenheimer was very close to the proposal at first that resulted in the [Bernard] Baruch report for the international control, and that subject came up repeatedly for discussion. We all felt that that was the way to go, to get an international control mechanism set up.

Sherwin: Were you involved with that?

DuBridge: Not directly.

Sherwin: First it was the [Dean] Acheson-[David] Lilienthal committee.

DuBridge: Yes.

Sherwin: My impression is that essentially the structure of that was very much the product of—that he did most of it.

DuBridge: That Oppenheimer did?

Sherwin: Yes.

DuBridge: Well, I am sure he did, because neither Acheson nor Lilienthal had very much technical feeling for it. He knew about the technology of the bomb, and the technology of the destruction process, and what kind of overpressures there would be at various distances, and all of that sort of thing of bomb damage.

He certainly was the technical man to guide that report, but he was very disappointed. He did not feel that [Bernard] Baruch handled the negotiations at all well, and he had felt that if Baruch had been somewhat more diplomatic and more sensitive, somehow or other that it could have gone further than it did. So he was terribly disappointed. He just felt that Baruch had not handled things well enough, and that was part at least of the reason for the failure of any agreement.

Now, it is possible no matter how well Baruch had done it, that there would not have been any. But at least at the time we still had hope that the Russians would be just as anxious as we were to get an international control.

Sherwin:  The years ‘47, ‘48, in that period, you were not only dealing with the question of the number of nuclear weapons, etc., but you were also dealing with the question of the quality. At some time in that period, the whole issue of the booster idea was developed, and the increase in size of atomic weapons to half a megaton, or something like that.

DuBridge: I do not think the fission weapons were ever visualized going that high, were they?

Sherwin: My sense from, for example, Herbert York’s book on Oppenheimer, Teller, and the Superbomb—

DuBridge: Well, he would know.

Sherwin: —hat by ’49 and the hydrogen bomb decision, the argument was that with this booster effect, you could get almost—

DuBridge: I see, I am a little bit vague about that. I know there was a great deal of discussion on changing the structure of the weapon and changing it so you are getting smaller ones as well as larger ones. Then, of course, came the hydrogen bomb, which solved the question of the bigger ones.

Sherwin: Now, could you try to recollect—a lot of the hydrogen bomb, all of the minutes and papers and letters that surround the period from September, when we first—early in September—

DuBridge: September?

Sherwin: Of ’49, when we first picked up the indications that this radioactivity that finally led to the conclusion that the Soviets had in fact tested a bomb.

The October 28th, 29th, 30th meeting of the GAC, the report that you are familiar with, came out, and then Truman’s decision at the very end of January 1950 to continue to move ahead. That whole six month period, most of the stuff has been declassified. But in terms of government reports, it is very wooden, in the sense of the conclusions and what was said in the reports. There is not the texture of the sense of concern and drama and anxiety and all of that, that was going on at this period of time.

DuBridge: Of course, you know the hydrogen bomb idea was already being batted around Los Alamos when I was there in 1945.

Sherwin: Yeah, people started in ’42, I guess.

DuBridge: So, in ’45 Hans Bethe and others told me about the idea of what they then called the “Super.” Theoretically they thought this could be done, but they did not know quite how to do it yet. In fact, they were a little bit puzzled in their calculations about cross-sections, and reactions, and so on. But they kept working on it. We would be briefed by various people, [Stanislaw] Ulam and [Edward] Teller, and others on the progress. Bethe kept in touch with it, too.

Sherwin: Do you mean from ’47 on?

DuBridge: Yeah, almost from the time we started the idea of the hydrogen bomb and the research on it was discussed in the committee. Oppie knew all about it.

Sherwin: Teller, of course, was thinking about it a long time.

DuBridge: Yeah, yeah.

Sherwin: Beyond that, was any part of Los Alamos actually—

DuBridge: When I was there in ’45, they were still pretty busy on the fission bomb, but the theoretical people were studying this whole question of how one could cause a fusion of hydrogen. They realized what the temperature problems would be, but they did not know quite what the cross-sections for the various reactions would be. They already knew that you could not just put four hydrogen atoms together and make a helium, because the chances of four of them uniting was so small. There had to be some intermediate stages. They would have to use deuterium or tritium, or a combination.

But then as we were briefed, it was, I think, Teller who carried most of the briefings to the GAC, although Oppie seemed to know as much about it as Teller did, even before Teller began speaking. Oppie actually would fill in various points.

But my impression, and the impression of the rest of the committee. was that every time we heard from Teller about the progress, it was regression and not progression. It got more and more difficult, and they were further and further away from having a practical idea as to how to initiate the fusion reaction. It was going to take more and more tritium, and tritium was harder and harder to get then. It was just my impression, that this was a long way off.

Sherwin: A long way off, definitely?

DuBridge: In time.

Sherwin: Or a long way off, if ever?

DuBridge: Well, I guess none of us doubted that it could be done. I do not think any of us doubted that eventually it could happen, but it was getting to look gloomier as to any immediate prospects. The effort required and the amount of tritium required was getting—as they then calculated it—beyond what we thought could be actually made available, produced in enough quantities. So we had a pretty gloomy feeling about the future. 

From my point of view, at the time we were asked to make a decision as to whether to go ahead with the crash program, I and Rabi and Oppie, others too, but I remember particularly how I felt, I said, “You do not start a crash program when you do not even understand the theoretical basis for this yet. A crash program you mount when you have a pretty good theoretical understanding of what you need, and a pretty good basis of what technology will enable you to get there.”

I did not see that in the reports we had heard about the H-bomb, briefings that we had. I felt that there was a lot of theoretical work yet to be done, and a lot of experiments on cross-sections and so on yet to be done, before one could even think of mounting a big crash program with dates and so on specified.

We had had a lot of experience with the Radiation Lab about when you start a major effort on a thing. We never started a major effort until we had had pretty well laid with small experiments or theoretical work and calculations, and examining the military requirements, and all the rest of it. Then, when we could see our way clear—not that we had all problems solved, but if we could see that the next difficulties were purely technical and not major theoretical or difficulties in principle—then go ahead with a big program, if there was the need for it.

I just felt that this was not yet ready for a crash program, to get everybody’s hopes raised that tomorrow we are going to have this Super program. That was at least my attitude and the recommending that we not go ahead with it.

Now, everybody on the committee had a slightly different point of view towards that. I remember Oppenheimer said, “How could we recommend a program on this thing, this object?”

Sherwin: In a disdainful way?

DuBridge: Yeah. “This object.” It is not a weapon yet and it is a long ways from it, and we do not yet see our way clear to make it a weapon. So how can you start a program on this object?

Sherwin: Would it be fair to say that you were as far from seeing how to do this as scientists had been back in 1942 before the [Otto] Frish-[Rudolf] Peierls [Memorandum]?

DuBridge: No, we were further back than that.

Sherwin: Even further back?

DuBridge: The experiments with uranium fission, laboratory experiments, the number of neutrons produced for fission and all of these things, and the theoretical basis for the energy release and all of the rest of it. The experimental verification of the amount of energy and experimental verification of the number of neutrons had all been done in the laboratory at Columbia and other places before [Enrico] Fermi went to Chicago to build one.

He already knew about the need for having slow neutrons to be more efficient in the fission and not fast ones. He therefore knew there had to be a moderator, something to slow the neutrons down, and used graphite. So the theoretical basis was sufficiently laid that I do not think anybody had any real doubts that it could be done. It was just a matter of how much uranium, how much graphite, and what the arrangement and so on would be the best.

Sherwin: The purity?

DuBridge: That is right. The purity was one of the sticklers too, of course, because they realized right away that impurities could have a disastrous effect. These things, I think, were clear. Nobody was surprised. I believe that people had followed it, that Fermi’s reactor worked. In other words, as I said, the theoretical basis for that was laid before Fermi actually started constructing the Chicago pile.

Now, that was not true of the hydrogen bomb as we saw it at that meeting, and that was the base of our recommendation. Now, it was not long after that that Ulam’s theoretical work had put a whole new light on the mechanism for initiating the fusion reaction. This was presented to the GAC at a meeting. It was in Princeton, I think. We had a meeting in Princeton, and this was presented to the GAC at that time. 

The nature of the theoretical approach was a little beyond my understanding, but Oppie got it right away and so did Fermi. They said, “Well, that puts a different light on it.” But that was after our recommendation had already gone to the president, or to the AEC.

Sherwin: What was the year?

DuBridge: I guess—well, it was sometime after. I have forgotten just what date that meeting was. We had two of them.

Sherwin: Bethe presented, gave the major presentation, didn’t he?

DuBridge: I think so, yes, yeah. I am a little fuzzy on just which happened when. All I remember is that the Ulam—I call it the Ulam Theory. Teller and Ulam still quarrel about whose theory it was. But anyway, this put a new light on it.

The idea there was, that the initiation could be accomplished by X-rays, by the enormous X-ray quantities emitted in the fission reaction, which would be enough to heat up fast the fusion, so it would go fast. Before that, it was just assumed that it had to be a pure matter of mechanical compression. Nobody realized what an important role the X-ray would place.

That was brought out in the Oppie movie. I am sure you saw that, the television show.

Sherwin: The Rabi?

DuBridge: No, the Oppie, the television show about Oppie.

Sherwin: Oh, yes, I saw that.

DuBridge: I think the actual details of what happened in that movie are not quite the same. It does not make any difference. The idea was that as soon as Oppie heard about this Ulam Theory, he said, “Well, that is beautiful. That changes the picture.” If that had happened, if the Ulam theory had been known to us before we were asked to make a decision, I think the decision might well have been different.

Although the reluctance to do it would have still been there, for as [James B.] Conant said, “For moral reasons.” Fermi did not like to use the term “moral” in connection with this, but he had other arguments. But a big thing, at least in my mind, was that it was not ready for a crash program, and it would raise false hopes. Furthermore, would just accelerate the arms race. If we could only say to the Russians, “Look, we could do this, but we do not want to, if you will agree not to.” But that never happened.

Sherwin: In a sense, the lack of this theoretical knowledge of how to do it was seen as a political advantage?

DuBridge: No.

Sherwin: In the following sense: that since we do not know how to do it and they probably do not know how to do it, let us take another try for international control. That’s what I mean by “political advantage.”

DuBridge: I do not think it was quite that flavor. I think what would have been said even if we were clear as to how to do it, we would have still proposed first. We would have recommended first to try to get an agreement with the Russians not to do it. But in a sense, this was also made a stronger case when we did not know how to do it anyway, so that we would not be losing time anyway, because they are going to take a long time to learn how to do it. In the meantime, we could start some negotiations.

Sherwin: Now, it is interesting to then move to the various sort of theories about what fuels the arms race. One of the arguments, of course, being the technological imperative and that Teller likes to latch onto this and say that if it can be done, it must be done, and if we do not do it, they will do it, etc. Aside from the fact that this is one of Teller’s favorite levers, I think, for prying things open, there is clearly an element.

Solly Zuckerman says the same thing. He puts it dramatically: the man in the laboratory who wants to build the new kind of weapon and recommends this. In other words, the driving force of science, the capacity of technology, etc., almost creates its own momentum. The story as you have told it suggests that there is a lot to that, in the sense that once it was theoretically clear how to do it, it was almost—given the context, of course, of a hostile international environment—almost irresistible, or irresistible.

DuBridge: Yeah, well since it had become clear that there was not much hope of getting any Russian agreement—as a matter of fact, there was not too much enthusiasm in the government about even trying, I think, at that time. Then clearly once it became clear that it was possible, there was nothing to stop it. There was no longer a reason for stopping it, since we had assumed that if we could do it, they could too, which, of course, they did.

Sherwin: Yes. Do you recall those discussions of October or any discussions prior to coming together, which was October 28th, 29th, 30th?

DuBridge: Well, only that we had had repeated briefings on the progress on the H-bomb and what the problems were and what the difficulties were. But then, we came to this direct request from the AEC to make a recommendation about going ahead with it. We were quite familiar with where it stood technically at that time. As I say, we were not very enthusiastic about the technical imminence of it.

Many people have asserted that Oppie came to this meeting convinced that our recommendation should be negative. Maybe he did, but he never said a word about his feeling about it. He says, “We have got this paper from the AEC requesting our opinion and advice on this plan—move ahead with the crash program. You all know about the status of the thing and so on. I want each of you, in turn, to say what you think individually.”

He never let on what his opinion was at all. We went right around the table. Everybody gave his view of it, and they were all negative. Some were for different reasons, a different flavor of the discussion, but it was unanimous.

Sherwin: I know, for example, that there were exchanges of letters, and perhaps even telephone conversations, between Conant and Oppenheimer before the meeting. Conant had said to Oppenheimer, “It is over my dead body.”

DuBridge: Yeah, I had forgotten that. That did not come up at the meeting.

Sherwin: Yeah. Other than that, there was nothing that you know of, at least, that the communication—certainly Oppenheimer did not talk to you?

DuBridge: No, but we saw this coming, I guess. We were not surprised when the question was finally put to us.

Sherwin: He did not tell you that he was totally against it?

DuBridge: Oppie did?

Sherwin: He did not?

DuBridge: No. I did not really know, and he certainly did not start out by saying, “Look, we have got to kill this thing.”

Sherwin: I see.

DuBridge: Everybody expressed his opinion individually and spontaneously. Then Oppie said, “I am glad we agree on that.” He did not force the committee onto this decision. He did not even attempt to exert any influence, by giving his opinion or giving the arguments against it. He said, “Look, the question is before us. What do you think?” One, two, three, four, five.

Sherwin: You were briefed by a whole line of people. I know [George] Kennan was one of them. Do you remember that?

DuBridge: No.

Sherwin: You do not?

DuBridge: Did he brief the GAC?

Sherwin: Yeah.

DuBridge: When was that?

Sherwin: He came in. Well, on one of those dates. People came in more or less one at a time. Bethe, for example, said that he spoke to you.

DuBridge: Yes.

Sherwin: Do you remember that?

DuBridge: Yeah.

Sherwin: Well, it was the same day Bethe did.

DuBridge: This is the meeting in Washington, at the AEC headquarters?

Sherwin: You were together for three days. I think it was the 29th of—whichever the last day was. I think it was the 30th. The report was dated that. For two days before, you talked among each other. You listened to representatives of the State Department, the War Department. Probably, I think, [Robert] Serber came?

DuBridge: I cannot remember. You would have to check the minutes on that. Yeah, we certainly discussed it. Of course, we wanted to get up to date on just where the thing did stand theoretically.

Sherwin: Someone like Kennan, for example, was talking to you about the Russian situation in general. He would not have had any scientific contribution.

DuBridge: No, I do not recall his talking.

Sherwin: Okay, well that is very helpful, though. I had not picked up with the kind of clarity you have given me, the sense of how in-touch the GAC had been with the hydrogen bomb prior to 1945.

DuBridge: Where do you want to go now?

Sherwin: Well, to the Oppenheimer hearing. I am almost not sure what to ask about that in the sense that, it’s such an enormous subject. I know you testified. I know sort of what you said and thought.

What was your impression of the hearing? How did you feel when you first heard about it? What do you know about Oppenheimer’s reaction to it? How close were you at the time?

DuBridge: We were pretty close. We talked at great length about it. I was first alerted to the fact that troubles were brewing by Jim Killian. I think we must have been at a President’s Science Advisory Committee meeting in Princeton. As I recall, this must have been the fall of ’52 maybe.

Sherwin: I will give you the dates and you can figure out how it fits in. Oppenheimer was first presented with these charges in December of ’53.

DuBridge: Yes, well, this was well before that. When Killian first got a hint—Killian had a way of knowing what was going on in Washington. I remember clearly we had a meeting of what became the President’s Science Advisory Committee, but at that time it was the Science Advisory Committee to the Office of Defense Mobilization. [Oliver] Buckley had been chairman of it, and he was retiring, and they asked me to succeed him as chairman of this committee.

Sherwin: Is [Dwight] Eisenhower president now?

DuBridge: He was just being elected. This was the fall of ’52, and it was about the time, I think, it was just after the election. The committee decided that we should go far beyond what the committee had been doing before. Buckley had the feeling that this committee should not be very active, just sort of keep its ears open and think about what we might do in case of another emergency. But the committee felt that there was much more that ought to be done. At that meeting, we decided that we would develop some ideas and present them to Eisenhower as soon as he was inaugurated, which we did.

But as an aside on that meeting, Killian whispered to me. He said, “People at the Air Force are going to be after Oppenheimer, and we have got to know about it and be ready for it.” Well, I was shocked and, in fact, half unbelieving that they would be seriously after Oppenheimer. But Killian was absolutely right.

Sherwin: What would be the date of this meeting?

DuBridge: As I say, it was just after the election in 1952. It was in the middle of November or something like that, yeah, November.

Sherwin: What was the meeting?

DuBridge: The meeting of the Science Advisory Committee of the Office of Defense Mobilization. We called ourselves the President’s Science Advisory Committee, because we did report to the president, Truman, through the head of the [00:39:00] office of defense mobilization, which was, I guess, was [Arthur] Fleming then.

Sherwin: Is Killian still alive?

DuBridge: Oh, yeah. He is at MIT.

Sherwin: At MIT? That is interesting. Did you pursue this at all with him? Who in the Air Force? Why?

DuBridge: Well, I am sure he told me who was behind it. I think it was a fellow by the name of General [Roscoe] Wilson.

Sherwin: Yeah, Roscoe Wilson.

DuBridge: Roscoe Wilson, it was, maybe. Whether Killian had talked directly to him or not, I do not know, but he got the word somehow. Killian was at other committees, too, in connection with defense work. So he picked it up from somebody. Since Oppie was also on the Science Advisory Committee, and we had been meeting not very frequently, but slightly more frequently in ’52, he [Killian] just felt this was going to be of great concern to the Science Advisory Committee, as well as to the GAC.

I did not hear much more about it for a while, except rumors kept coming that there were troubles brewing, and we were all terribly worried about it. Charlie Lauritsen was on the Science Advisory committee and he was very close to Oppenheimer. He was terribly concerned and worried about it.

Sherwin: Did anyone alert Oppenheimer?

DuBridge: I do not know if or when. I never said anything to him about it. Whether anybody else did or not, I do not know. I think he felt something was brewing. He was too sensitive to be unaware of the fact that there were troubles.

Then it finally came and the charges were presented, and a hearing was set. Many of us had long discussions about it. I talked to [Charles] Lauritsen, with Rabi, with Bacher and with Oppenheimer, too, after the thing was out in the open, and Killian. Then as the hearing approached, we met with Oppie’s lawyer on a number of occasions.

Sherwin: Which one?

DuBridge: What was his chief lawyer?

Sherwin: Lloyd Garrison.

DuBridge: Lloyd Garrison, and met with him to a considerable extent. He was sort of checking with the people that he thought should be willing to testify on Oppie’s behalf. Of course, Rabi, myself, Charlie Lauritsen, and so on were all glad to do what we could.

The hearing itself was just a real star chamber. It was really scandalous that this kind of hearing would be conducted. There was no advance notice to anybody of what materials would be presented or questions would come up. It was just a grilling on the part of the AEC lawyer of each—

Sherwin: Roger Robb.

DuBridge: Yeah, of each of us in turn, and completely loaded questions. It was pretty awful, as you could gather by reading the testimony. Insinuations, you know, and loaded questions, and slanted questions. They were just impossible to answer, you know?

Sherwin: Let me just sort of backtrack a bit and tell you what the implications of some of the things that you have said are to my mind. If you think I am wrong, straighten me out.

If we know that as early as 1952, there were people in the Air Force that were out to get Oppenheimer—this is in the McCarthy period, of course—and that he was a target of a conjunction of interests who saw him as “dangerous,” and they finally got him. In technical legal jargon, that is conspiracy. In effect, he was accused of a conspiracy to prevent the development of the hydrogen bomb.

DuBridge: Yeah.

Sherwin: This is extraordinarily interesting. I have never seen this before or in any way come across it, that a year earlier there was this awareness on the part of some people that there was—

DuBridge: Things were stirring then, yeah.

I do not know whether in any of the McCarthy hearings Oppenheimer’s name had come up or not about that time, the McCarthy hearings. Anyway, this was the first inkling I had, when Killian whispered it to me and said, “We have got to be on the alert and think about what to—”

[Tape switch.]

DuBridge: I do not know about the legal definition of conspiracy, but there certainly was a group that decided that Oppie was a dangerous character. Of course, they brought up all his past associations in Berkeley, which was years and years before, all of which had been looked into by [General Leslie] Groves and others, before he was ever brought to Los Alamos. We knew about those, and we knew about the clearance troubles he had there. [Robert] Bacher had told me and others. So this was rehashing old ground.

But I think it was Lewis Strauss who was especially after him. He was indignant at the H-bomb recommendation. He just accused Oppie of having swung that to his advantage, and that he had hypnotized the other members of the GAC into going along with him, which is—as I have told you—very, very far from the truth, because it was a unanimous, spontaneous decision.

It was one of the most awful times, because it split the scientific community very badly. Some of the people I thought were good old friends of mine denounced me for even thinking of supporting Oppenheimer.

Martin Sherwin: That would be [Ernest] Lawrence?

DuBridge: Lawrence, [Luis] Alvarez, Dave Griggs.

Sherwin: The Berkeley crew. Well, Griggs was at the Air Force. He was the Air Force scientist.

DuBridge: Yes. That is right at that time. He later came to UCLA, but that was later. He was at the Radiation Lab, so he and I were good friends there.

Well, Luis Alvarez and Ernest Lawrence and others had been good friends before. But this was a ghastly, bitter, bitter split. You can see the way the people lined up in the testimony. I never talked directly with Teller, but we read his testimony.

All of this has been hashed over in plays, books and TV. I thought the TV presentation was pretty good.

Sherwin: I thought that the acting was superb and the casting was extraordinary.

DuBridge: Yeah. Some of the settings that they used for some of these discussions and things were different physically. But that was unimportant. The ideas were there.

Sherwin: But I thought that some of the characters were—given the level that one expects from BBC—too one-dimensional. Like Kitty, she could behave that way without any question. I know that from a lot of interviewing.

DuBridge: Oh.

Sherwin: But there was also another dimension to her.

DuBridge: Yeah.

Sherwin: There was also an evolution from 1940 to her worst year.

DuBridge: Well, she was a strange character. There were at least two sides to her. My relations with her were always very friendly and very warm. As I say, I visited at Oppenheimer’s house in Princeton a number of times when she was there, either alone or with others. I remember Niels Bohr was there one time when I was.

Bacher and I were there together on many occasions. They came out here a number of times. See, way back in the late ‘40s, we had the Vista Project at Caltech that Oppenheimer was very active in.

Sherwin: I asked Bacher about that, whether there were any Vista Project reports or papers around. Are there any you have kept?

DuBridge: I think they were all so highly classified that they were all simply sent to Washington, and we got them out of our files. You could probably find them in Washington someplace.

Sherwin: Oh, yeah. I meant more of the—rather just the reports.

DuBridge: No, there were no published documents. We had a series of top secret reports that we submitted to the Air Force and the Army. That was brought up in hearings.

Sherwin: Yes.

DuBridge: This is one of the sad slants that was never brought out much in public. But it hit me because when I was testifying, [Roger] Robb put before me a copy of one of the volumes of the Vista Report, the one on nuclear weapons, tactical nuclear weapons. In that report, it said, “We conclude that the hydrogen bomb would have no use in tactical warfare. There was no tactical application,” or something of the sort.

Robb said, “You signed this report and Oppenheimer had something to do with it. Was that a correct statement of what you believed?” I said yes. And he said, “That’s all.”

It only dawned on me later that he did not know what “tactical” meant. He thought this was a flat statement that we thought there was no military use for the hydrogen bomb. That was the implication.

Oppenheimer felt there was military use for the hydrogen bomb. What we meant was on the battlefield, there was no place. We were specifically ordered to have nothing to say about strategic warfare in the Vista Report. We got that from high up, and we had no intention anyway, because the whole idea was what to do on the battlefield. We were talking about tanks, artillery, troop movements, troop training. Then the question of whether small fission weapons might be of use on the battlefield came up. Of course, that might be a possibility. There were then small fission weapons being developed.

But that was the kind of thing, that he would twist anything. Whether he did it intentionally or whether he did not even know what tactical—

Sherwin: Oh, he knew. He was quite a—

DuBridge: Curiously enough, have you read Leona Libby’s book?

Sherwin: No.

DuBridge: Leona?

Sherwin: Leona Libby?

DuBridge: Life, yeah.

Sherwin: She was a physicist.

DuBridge: She was Leona Marshall, and her husband [John Marshall] was a graduate student of mine at Rochester. He went to Chicago, the Chicago group, and Leona was there. They were married, but they each had their own careers. She was a physicist and he was a physicist. Who was my student at Rochester. He got his PhD there in physics, then went to Chicago. They met there and were married. She still called herself Leona Marshall Libby, but they had separate careers. They always seemed to end up on jobs in different towns. It was a marriage of commuting, and it finally broke up and they were divorced. Then she came to UCLA. Willard Libby was there. His wife had died, and then they were married. Of course, he later died.

Anyway, she brings up this same business about the Vista Report. I think she quotes it as saying that there was not any tactical use for the hydrogen bomb. She again indicates that that meant that we were blind to the fact that there would be strategic uses, military uses. She also apparently did not understand the difference between tactical and strategic, in spite of the fact that the whole flavor of our report was on tactical warfare. I just thought that was understood.

Sherwin: Okay. There was a lot of discussion of tactical warfare as opposed to strategic?

DuBridge: That is right, yeah, and this whole project was set up.

Sherwin: There was the Rand Corporation. They were doing a lot of stuff.

DuBridge: Yeah, I know. This whole project was set up by people in the tactical Air Force and the Army.

Sherwin: Yeah.

DuBridge: We were listing tactical air support, among other tactical problems. Anyway, that is just a side issue.

Sherwin: I have been asked on occasions as I have given lectures. I teach a course called America in the Nuclear Age, and I cover a lot of these issues. My view is very strongly that the GAC was right for the right reasons for the hydrogen bomb, etc. I reviewed York’s book, for example, in the New York Times. I can recall making that statement.

The question that is often asked me is, “Well, they were wrong. An H-bomb was possible, and the fact is that tactical nuclear weapons, the smaller nuclear weapons, today are hydrogen bomb weapons.”

DuBridge: Not the battlefield ones, I do not think, are they?

Sherwin: Are most of them?

DuBridge: I think there are still fission weapons. There are only a few of them. One, the 5 – 10 kilotons. that sort of thing. They are small.

Sherwin: I see.

DuBridge: They are much smaller even—

Sherwin: Those are all—

DuBridge: That is what we were talking about.

Sherwin: And those were the ones—

DuBridge: Yeah, I think so.

Sherwin: Is there a miniaturization limit to what you can do with hydrogen bombs?

DuBridge: With hydrogen bombs?

Sherwin: You mean, you cannot make them smaller than X?

DuBridge: I cannot answer that. I cannot answer that. I think it is not easy to make them as small as you can a fission bomb.

Sherwin: A fission bomb.

DuBridge: Yeah, and these artillery weapons, I think, are all fission bombs.

Sherwin: And there is no particular advantage to using the hydrogen bomb?

DuBridge: No, if you only want a few kilotons or so, and you want to limit the damage just to a tank concentration, a troop concentration, a transportation center or something just behind the lines, there is no use of having a thing with a megaton.

That was our idea, that something more powerful than ordinary artillery or 500 pound bombs from airplanes would be useful. A nuclear warhead would be suitable for that. There are 500 or so of these artillery-type weapons in Europe now.

Sherwin: Oh, there is more. There are 8,000 nuclear warheads in Europe. I do not know how many are artillery shells, and how many are things that are loaded on—

DuBridge: I guess I was thinking more of launchers than of actual warheads. I do not know the number of warheads.

Sherwin: Yeah, I think there were 500 launchers.

DuBridge: Yeah, yeah.

Sherwin: And there were warheads [inaudible].

DuBridge: Yeah, yeah.

Sherwin: The visit that you, [Charles] Lauritsen, and Oppenheimer made to Europe, to SHAPE [Supreme Headquarters Allied Powers Europe] Headquarters. Was that not also held, in a sense, against Oppenheimer? Because I remember finding some correspondence that said, “Oppenheimer is going over there to talk [Dwight D.] Eisenhower into something.”

DuBridge: Yep. Yes, the people in the Air Force were very much disturbed about our visit there. They still had not got the point that we were talking solely about tactical battlefield problems and not strategic warfare.

Sherwin: I think to a large degree the Air Force was very competitive. A certain amount of money—

DuBridge: That is true.

Sherwin: Maybe the Army gets some of this nuclear—

DuBridge: Yeah. That is true.

Sherwin: We are going to lose some of it.

DuBridge: Yeah. That is true. That was that. But they just did not want us to get into the strategic warfare at all. Actually, we were going to talk with Lauris Norstad, and we did. But John McCone, the Secretary of the Air Force then, and some others called Norstad back to Washington to tell him, “You tell those sons of guns to keep their nose out of the strategic warfare business. They do not know anything about it. It is terribly important that they do not start parading their opinions on strategic warfare over there.” We had no intention of doing that.

Sherwin: This is John McCone?

DuBridge: Yeah.

Sherwin: The fellow that became head of the CIA at one point?

DuBridge: Yeah, yeah. He was secretary of the Air Force then, I think.

Sherwin: Yeah.

DuBridge: When we finally did see him, he had just come back from Washington, and he dutifully repeated this thing. We just smiled and said, “Look, Lauris. We had no intention of getting into that. That is not our business.”

He says, “I know that. But I had to tell you what they told me.” Then, we went ahead and got down to the business of tactical. He was head of the Tactical Air Force in Europe, you see, not the strategic.

Sherwin: All right.

DuBridge: His title was commander of the Tactical Air Force in NATO. We had a fine talk with him. We had a good talk with Eisenhower, and so on. We had many visits to Army and Tactical Air Force headquarters in Europe. It was a fascinating trip.

By that time, Oppenheimer was a hero. I was chairman of this group. But whenever we went to a new Army or Air Force place, it was Oppenheimer they greeted. He was the one that everybody knew about. He was the hero. That was fine with me. So at that time he was a great hero over there.

Sherwin: Was this a—should I say exotic trip, or very stimulating trip?

DuBridge: Yeah, it was very informative, very stimulating, very interesting and very helpful in writing in our report, because we got the feeling that—you see, we were told to do a study of tactical warfare. We decided to make it concrete. We would say, “Let us assume that the Russians invaded Western Germany. What do we do? What are the things that will be needed to combat that invasion? Do we have the equipment? Do we have the proper kinds of tanks and artillery, troop movements, troop training and all the rest of it?”

So we got a lot of information there. We visited many posts in this country too, and they put on elaborate demonstrations for us, artillery things, parachute drops, mass parachute drops and so on, at various Army bases around the country. It was an extremely educational thing. We were just given royal treatment at every place we visited, because the top people in the Army and the Tactical Air Force were behind us.

Some people later said that the Vista Report was not very good. Well, it was not very good. It certainly was in line with the thinking of the Army and the tactical Air Force at that time, supplemented by what we could tell them about new kinds of weapon technologies that could be used. Matter of fact, Jerry Wiesner ran into a copy of the Vista Report when he went to Washington as [President John F.] Kennedy’s science advisor. He got it out and read it. He said, “By golly, that is a wonderful report. It was just as good today as it was when you wrote it.” He says, “It was too bad nobody had paid any attention to it.”

Sherwin: Well, in a sense though, it really was a blueprint for the tactical nuclear defensive [inaudible] of Europe.

DuBridge: That is right, yeah. There are many other things that they followed. We proposed setting up an experimental combat division to try out new technologies. They hesitated a long time, but finally did. I do not know if it still exists or not, I guess probably not.

So some of the things were followed. Those who were close to the people in the military who were close to this, they said this was a fine job. They participated in every sentence of their final report, so it was certainly in line with the military thinking at that time. The only changes in military tactics which we recommended were those that were made possible by some different kinds of weapons, tankers, nuclear weapons or whatnot.

Anyway, Oppie was very active in that group. Of course, that was another thing that they thought that this was against strategic weapons. They held that against Oppenheimer.

Sherwin: Let me ask you. This will be the last question. Was there any concern or discussion about the expansion of the nuclear armaments to the area in which conventional warfare had dominated before, or Army conventional forces with nuclear weapons? Was a problem that there were dangers involved?

DuBridge: I think we probably minimized—as I look back on it, we probably would not have said the same thing now. I think the idea that small weapons used in a battlefield situation took place just behind the lines within a radius of twenty, thirty miles over the front. We thought nuclear weapons would be useful for wiping out tank and other concentrations.

I think at that time the idea that this would escalate into a major strategic nuclear warfare was not very clear, or we did not believe that that would necessarily follow. Otherwise, we probably would not have recommended it so specifically. I would not do it now, I guess.

But still, weapons are there now anyway, and they are not even discussing those weapons, the battlefield weapons. They are discussing the intermediate weapons, the 100,000 miles and the Pershings and so on and SS-20s and so on. But they are not discussing the artillery.

Sherwin: One of the things that concerned the Air Force, one of the ironies that is involved in this whole thing is that—again, if I am wrong, please tell me. It is my impression that Oppenheimer, at least, had a great distaste for the fundamental orientation and philosophy of the nuclear strategic people, who were extraordinarily crude in their orientation of “Bomb them back to the Stone Age” [General Curtis] LeMay type of thing. The idea that warfare was being planned as genocide, an obliteration of the Soviet Union. “We killed two hundred million of them in the first four hours,” or something like.

This was, to say the least, a rather barbaric approach to international problems and even to warfare. It was in the wrong hands. These things were too powerful. Nothing left, no hope, nothing positive in it. The reorientation or additional orientation towards tactical weapons held out the possibility of modifying or bringing under control this Strategic Air Command group that was so barbaric in their orientation.

DuBridge: I never heard him say anything along those lines.

Sherwin: Well, these are not his words, per se.

DuBridge: No.

Sherwin: But I mean it is my—?

DuBridge: It is your feeling. It could be. I know, as many of us were, we were terribly worried about the strategic nuclear arms race. Is there not a way of coming to an agreement and getting it stopped, and so on? I am sure he felt very deeply about it. I would not have suggested that he thought that the tactical weaponry was a way out of that. It was a way to maybe prevent the invasion of Western Europe.

Sherwin: Or at least if the invasion occurred, of not responding in this—

DuBridge: With a massive—

Sherwin: Horrendous—

DuBridge: Yes. That is right, yeah. Yes. I think that would be right, yes.