The Manhattan Project

Hans Bethe's Interview (1982) - Part 1

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Hans Bethe was a German-American physicist and Nobel Prize winner who was head of the Theoretical Division at Los Alamos. He played an important role in the development of the hydrogen fusion bomb. In this interview, Bethe discusses the decision to develop the H-bomb in a starkly different context compared to the A-bomb. He recalls the debate over MIRV, the rise of the nuclear race, and missed opportunities to promote nuclear nonproliferation, including the Cuban Missile Crisis and Bernard Baruch's plan.
Manhattan Project Location(s): 
Date of Interview: 
May 5, 1982
Location of the Interview: 
Ithaca
Collections: 
Transcript: 

Martin Sherwin: This is an interview with Hans Bethe in his office at Newman Hall, Cornell University, May 5, 1982. This is Martin Sherwin.

Sherwin: I’m glad I caught this. Basically, you were surprised that Kyoto had been selected and at these meetings, that the Target Committee had been held in the Oppenheimer’s office.

Hans Bethe: That is correct. And what we were told was that the two places which were actually bombed later on, and the two alternatives, all had considerable military value, I think, and I don’t recall precisely what these military values were. I think Hiroshima was a staging area, Nagasaki was obviously a very important port, and Kokura, which was one of the others, had a similar value. So their selection was, I think, primarily on a military basis.

Now, I do not know whether there were any military targets, which were not in cities. And so I do not know whether the alternative existed of selecting a target, which was only military and would not involve a major city. I just don’t know. But it would be important to try and find out whether such existed.

Sherwin: Well, what I have and what is in the book is quotations from the minutes of the Targeting Committee. They talk about the criteria that they were using to select it. The criteria points toward selecting a target that would be the largest piece of real estate that you could destroy.

Bethe: Yes.

Sherwin: And they wanted a target that would be destroyed. But I think it’s best to look at the actual documents.

Bethe: I didn’t know. I did not know either how strongly [Harry] Truman wanted to use the atomic bomb later, after the end of the Japanese War, as pressure on the Soviet Union. You indicated that already in the manuscript that he did want it as pressure, but what you report is much stronger than what I had read in the manuscript.

I want to remind you—and I’m sure you know that, at least as well as I—that after the end of the World War II, the Russians had tremendous superiority and conventional strength in Europe, that Western Europe was completely dominant. And that the atomic bomb was then used as a counterweight. At that time, this made sense for both reasons, namely that there was no European force to counter the Russian, and that we had the monopoly of atomic bombs. I think this makes your case stronger, rather than weaker, because that was an example where actually atomic diplomacy, if you want to say, or the threat of atomic retaliation did make sense. But the two reasons have to be combined.

Sherwin: Yes.

Bethe: I think now, all that has changed, and for Reagan’s government to repeat the words of the Truman government makes no sense because if nuclear war were started, it threatens us at least as much as the Russians. And so it is no longer a useful threat against the Soviets. It also is no longer true that the Russians have great dominance in conventional weapons. Of course, they have enormous manpower, of course, they have very large numbers of tanks, and of course, they have been building up their conventional strength quite strongly in recent times. However, their allies are not dependable. I think our allies are dependable, as long as they are not afraid of being destroyed by our trying to save them. And I think the situation has changed completely, and so, the Reagan government simply cannot go back to that old example.   

Sherwin: I think tying it together, the problem is, the situation has changed.

Bethe: Totally.

Sherwin: But the mindset has remained.

Bethe:  At least in the minds of the people now in the government. Now, you mentioned several times, or let me put in one more point—there were, I believe two occasions in which the threat of nuclear war was used against the Soviet Union rather than against minor powers. One was Berlin, 1961, when it was quite unclear what the Russians had in mind. I think it is still quite unclear what they had in mind. [John F.] Kennedy used the threat of nuclear weapons at that time. At that time of course, we had still tremendous superiority, although certainly not a monopoly.

Sherwin: What is your understanding of how we use those, that threat? The public announcement?

Bethe: Public announcement. That’s the only thing I know.

Sherwin: I was just wanting to see if it was additional –

Bethe: If there was, I do not know.

Sherwin: Okay.

Bethe: And the second was in the Cuban Missile Crisis. Now, I have always believed—and certainly every Navy person confirmed—that the Cuban Missile Crisis was won, not by the threat of nuclear weapons, but by the American Navy. It was in our home waters, we were right there, we had a tremendously strong Navy. We could do whatever we pleased with or without nuclear weapons. And I think the background of nuclear weapons was unimportant, except to the extent that we surely could cause a major threat on that point of view.

I would discount the other uses, or at least I don’t think they are really important. The point in which my opinion is the most important, is the succession of missed opportunities. Obviously, the 1946 negotiations in the United Nations was doomed to failure, because the Russians did not want to be a second-class power. And whatever we might do, they would have refused. Now, we also didn’t present it very well. We should have Mr. [Dean] Acheson present it, rather than Mr. [Bernard] Baruch. But that’s beside the point.

Sherwin: Excuse me for interrupting, but maybe part of the point—my view of the Baruch presentation, and my understanding having looked at a lot of the documents of Truman and Acheson discussions about the Baruch Plan, was that they really never took it seriously. In that, they never expected the Soviets to accept it, given the way it was constructed. And therefore, it was better that Baruch present it rather than Acheson.    

Bethe: I don’t believe this. I would go further you did. Certainly, Baruch did not want it to succeed. I think Truman was of divided mind, and was terribly afraid of Senate confirmation. The Senate, I think, had a majority against it.

Sherwin: Probably did.

Bethe: So Truman appointed Baruch as a great conservative, so that he would a somewhat better time in the Senate dealings. Surely, it was not presented in an attractive way.

Sherwin: Yes, the first missed opportunity, which I always have to insert, was [Niels] Bohr’s initiative.

Bethe: Yes, yes, and you describe that extremely well in your book, and I think you are right. So then, the next, when you’re counting, the third opportunity was the H-bomb, and we’ll have to talk more about that later on in detail. I haven’t read [McGeorge] Bundy’s article in detail, but I thought he had the right idea. You seem to disagree.

Sherwin: I think he’s looking in the right direction, in the right place, but he qualifies his discussion so much that I think he almost ruins a lot of it. Basically, what he argues is that we should have had an initiative, the kind of initiative that no one suggested. Now, if no one suggested it, it is hard to argue that it was a possibility. 

Bethe: The kind of initiative, namely to say, “Develop it, but don’t test it.” Is that right? Do I understand you right? I haven’t read the article, but only peeked at it. And so I would like you to specify just what you mean.

Sherwin: Well, I read it a while ago and it creeped into my talk. What he really should have developed, it seems to me, is this comment that he makes on the first page where he says, “And when the decision was made, there was no audible complaint of the way it was made. By habits that had first been set in wartime, and then set in concrete, by the belief that the secrets of the atom were crucial to national survival itself, the decision was left to the President.”

And then he leaves that and goes into arguing that there should have been an initiative and was different, for example, than the one in the [Isidor I.] Rabi proposal, the Rabi-Fermi proposal, and the one that was different and the one the rest of you signed. Now it seems to me that what we have to go with is what was thought of, at one place or another.

I think what we should have gone with were those initiatives. See, he in some way weasels out of, I think as I read it the one time.

Bethe: Yes, since I haven’t really read it, but doesn’t he mention prominently the idea of agreeing that we shall not test it?

Sherwin: Yes, but once you start to build it in secret and in commitment, the idea that we would be able to stop suddenly, strikes me as somewhat naïve.

Bethe: I don’t think so. I don’t think that is naïve at all. I think, in fact, it was the only possible way, in retrospect. I didn’t think of it at that time, but only thought of it much later when I became aware of the tremendous visibility of these tests.

Sherwin: Uh-huh.

Bethe: It is perfectly reasonable to say, “You should go ahead and get ready, just in case the other person tests it.” And if we had done that, and then the Russians would have made the test, we could, in a very short time, have matched them.

Sherwin: But wouldn’t it have been better to – I don’t know, approach to try and even prevent getting to that point where, is all you have to do is test it? It’s almost like developing the cruise missile.

Bethe: It would have been better. But that’s not the point. We, in one of the documents you gave me, it says that we could not afford to leave it to chance, that the Russians might develop it, and that the President’s decision probably was the only possible one. We did not know, and we do not know today, what goes on in the Soviet Union.

At that time, it was much worse than it is now, because [Joseph] Stalin was the dictator and not [Leonid] Brezhnev. If it had been Brezhnev or [Nikita] Khrushchev, it might have been possible to agree not to develop it at all. But certainly, with Stalin, this was impossible. And therefore, just to safeguard our country against the surprise, I’m afraid Truman had to decide to develop it, but he could have stopped short of testing it. I’m sure that the scientists involved in the development would have cried bloody murder, but they are very few. But how much worse would it have been if we had not even developed it, and then the Russians confronted us with a ready test. 

Sherwin: But what about the GAC [General Advisory Committee of the Atomic Energy Commission]? This gets us right to the issues at that October 29th and 30th meeting.

Bethe: Yes.

Sherwin: What about the argument that Herbert York accepts, that if we stated we were not going to develop the hydrogen bomb, but that we were going to develop a sufficient boostered atomic bomb stockpile, that it was sufficient to act as a deterrent? And according to the report that they made you sign, along with Oppenheimer, right?

Bethe: With Oppenheimer? No.

Sherwin: You signed—well, the report that Oppenheimer signed.

Bethe: Yes.

Sherwin: One of the recommendations said that we have sufficient—even if, the one [James B.] Conant wrote, I guess, that even if the argument is made, that you know, the Russians [inaudible], we have sufficient –

Bethe: I strongly agree with that. And this was publicly stated in one of the articles in “Scientific American” in the spring of ’50. I think by [Louis] Ridenour, it may have been by [Robert] Bacher. You’ll remember there were three articles, these two and mine. And this argument—quite independently of the committee, because the committee didn’t tell anybody what they have decided—this argument certainly was a strong argument, perfectly valid argument. Nevertheless, in public perception, Truman might have looked very bad if the Russians had come out with an H-bomb and we had nothing.

Sherwin: If we only had atomic bombs.

Bethe: If we only had atomic bombs. From a military point of view, the GAC and York, and you are certainly perfectly correct that it would not have change the balance of power.

Sherwin: I guess that’s another way of putting the problem that we’re stuck with.

Bethe: Yes.

Sherwin: What I was talking about.

Bethe: Yes.

Sherwin: That if in fact, we would have been secure by doing less. Maybe not as secure, but secure enough.

Bethe: Yes.

Sherwin: By doing less, but because of public opinion, the view that the public has of this, that the President was forced to develop the hydrogen bomb, then that’s the problem.

Bethe: You’re absolutely right.

Sherwin: And the President did nothing in the period from ’46 – did very little to counter that opinion. On the contrary, I think the administration reinforced that opinion, that the bomb was something that provided our security.

Bethe: The atomic bomb?

Sherwin: The atomic bomb. And of course, for the public, the atomic bomb is good, the hydrogen bomb is better.

Bethe: Well some part of the –

Sherwin: Yeah, public.

Bethe: – public.

Sherwin: But that’s a serious problem.

Bethe: Yeah, that is a very serious problem. One always has to see what is possible. And certainly, the line which I mentioned would have been perfectly open, and could even have been successful, namely to say, “All right, let’s develop it. We don’t want to test it, and we’ll tell the Russians exactly that. And we’ll tell the Russians, if they test it, we’ll do the same.”

I want to add to this that the H-bomb, in contrast to the A-bomb, is useless unless it is tested. It is sufficiently complicated and there are sufficient unknowns in designing it, that nobody could put it into a stockpile without first testing it. Whereas the atomic bomb, if you have some competent scientists and the material and the knowledge, which is public, you can very easily put everything together and have a stockpile without ever testing it. And many people believe this is what Israel has done.

Sherwin: This is for implosion?

Bethe: Absolutely implosion, that’s the only thing that makes any sense. I think Israeli scientists would be completely capable of doing this, and having a reliable weapon, without ever testing it. The same I think is true of Germany or Sweden or Switzerland or Italy, but not of Pakistan or Libya. But with the H-bomb, it is different.  

Sherwin: Is it still different today?

Bethe: It is still different today. Nobody can design an H-bomb, build an H-bomb, and expect it to work without first testing it. He may only test a minor yield addition, he doesn’t need to make a test like our Mike in 1952. But he has to make a significant test, surely observable.

Sherwin: Of the what?

Bethe: Surely observable.

Sherwin: Observable? 

Bethe: From abroad. And without that, its military couldn’t possibly trust the gadget. This I think was known in ’49, that it would be a very complicated design, and that therefore this avenue was open. It was known even better in ’52, just before the test was made.

I would say one thing on behalf of Paul Nitze, who is now a terrible hawk, he was one of the people who immediately before the Mike test, said, “Delay it, don’t do it. At least the new President should have an opportunity to say whether it should be done.”

There would have been a perfectly good chance that [Dwight] Eisenhower, who was fundamentally very peaceful, as we know from many of his statements, would have said, “All right, let’s further delay it.” And if it had been further delayed, then Stalin would have died and then we could have approached Khrushchev, and with Khrushchev, we might have been able to agree.

Sherwin: So if this suggestion was made in ’52, that is yet another missed opportunity, ’52.

Bethe: Right.

Sherwin: That is even more interesting and relevant than ’49, because in ’52 the suggestion was actually made.

Bethe: It was made.

Sherwin: Yeah.

Bethe: It was made, and I am not entirely sure who was the initiator.

Sherwin: How did you hear about it?

Bethe: I heard it from Oppenheimer.

Sherwin: Oh, how did Oppenheimer feel about it?

Bethe: He was, I think, in favor of it. But he was not involved in it. It may have come from Bush, Vannevar Bush.

Sherwin: Yes. You mean the idea originally?

Bethe: The idea.

Sherwin: May have come from Bush. Why do you think it might have come from Bush?

Bethe: Because I vaguely remember that that was mentioned at the time. I don’t know the document. I think I saw the document in November ’52, just before the test was made. It may have been just after the test was made that I saw the document. I believe it was classified only “Secret.” Maybe “Secret” or “Restricted data,” I don’t know, probably. But not “Top secret.” And it may now be declassified. I am pretty sure that Oppie had a copy, and so it may very well be in the archives of his papers.

Sherwin: So it would be a –

Bethe: A letter from – let us say Bush with the concurrence of [Paul] Nitze, to possibly Truman, possibly to the Secretary of Defense—there was no Secretary of Defense—possibly – I don’t know. To somebody high in the government.

Sherwin: Well that’s when Acheson was Secretary of State and Nitze had [George] Kennan’s job, which was head of the Policy Planning Staff in the State Department.

Bethe: Yes. So it might well have been directed to Acheson. I know that letter existed, I hope it still exists. I think it was an excellent idea. I didn’t, at the time, realize how good an idea it was. Among other things, nobody could foresee that Stalin would die within the year.

Sherwin: That’s a very interesting piece of information.

Bethe: Okay, that was opportunity number three.

Sherwin: No, no, that’s four.

Bethe: You consider – okay.

Sherwin: The war is first, the Lilienthal report second, H-bomb is third, and this –

Bethe: H-bomb testing.

Sherwin: —is number four.

Bethe: Now, next opportunity, as far as I can recall, was 1961. We had been told about the missile gap. And [John F.] Kennedy was elected on the basis of the missile gap. And Kennedy surely was a very intelligent, perhaps the most intelligent, of the post-war Presidents. And Kennedy was certainly a man of peace. It became clear during 1961 that the missile gap existed in reverse. That the Russians didn’t have anything, that in fact, their deployment came after ours and not before ours.

Sherwin: And what they had was completely vulnerable.

Bethe: Yes, liquid.

Sherwin: Liquid fuel.

Bethe: Fuel and so on and so forth, yes. Okay, if Kennedy and his advisors had been really alert, they could have said in ’61, “All right, we do deploy the Minuteman, but we stop at 200.” He could have got away with it, because he did have that intelligence available to him. He had one of the best science advisors ever, [Jerome] Wiesner, who surely was aware of it. And he had one of the best Secretaries of Defense, [Robert] McNamara.

I think it is really a sin that these two didn’t tell Kennedy, “Mr. President, let’s stop the thousands, don’t make any sense, let’s stop at 200. We have the pattern if we need more. If the Russians build more, we can always build more.” And that was a tremendous missed opportunity.

Sherwin: I agree, again.

Bethe: And it is one which I think is seldom mentioned.

Sherwin: Yes. No, I agree. I mean, I talk about this historical event.

Bethe: Yes, yes.

Sherwin: But I’ve never thought about that reverse missile crisis as a missed opportunity, since again, nobody was talking about it.

Bethe: All right, next, 1967. The MIRV.

Sherwin: Oh, yes.

Bethe: We invented the MIRV, that is the United States. I was on a committee, a sub-committee of PSAC [President’s Science Advisory Committee], on strategic weapons. It was perfectly clear to all of us on that committee that MIRV was destabilizing. In fact, one time, one of our members was Merv Goldberger, who once didn’t come to the meeting, and somebody said, “Well, Merv hasn’t come because he knows that he’s destabilizing.”

And around that time, I think it was a year later, the arms control agency wrote a very impressive and very well recent [reasoned] paper saying, “Look here, what you’re starting here is a weapon, which is much more to the advantage of the Russians than to ours. Because they have these big missiles, they had those already. We have much smaller missiles.”

Sherwin: We can put three, they can put ten.

Bethe: Right, and ten bigger ones than we have. “So don’t do it,” essentially, what they said. “And when you negotiate an arms control treaty,” which was imminent at the time, “Please remember that this is a weapon, which will, in the course of time, be to our disadvantage.”

Until then, ICBMs had been perfectly stable. You needed at least one missile to destroy an ICBM silo. Nobody in his senses would try to do this, because you would need at least two missiles to have any certainty. So therefore, at that time, ICBMs  were perfectly safe, secure, and stable.

Sherwin: As long as both sides had about the same number.

Bethe: Yes, What number is this? Five?

Sherwin: Five.

Bethe: And this is probably more significant even than some of the others.

Sherwin: Can I ask you some questions about this?

Bethe: Please.

Sherwin: This board that you were on that dealt with MIRV, the PSAC board.

Bethe: Yes.

Sherwin: Was this a special subcommittee to deal with MIRV, or was this the PSAC board?

Bethe: It was a PSAC panel on strategic weapons.

Sherwin: Was everybody a member of the board, or were you consultants to PSAC?

Bethe: We were members of that subcommittee, and I was not a member of PSAC anymore. There always had to be at least one member of PSAC on the subcommittee. But the others could be different people, some of whom had been on PSAC before, as I had, and some of whom had never been on PSAC.

Sherwin: Uh-huh.

Bethe: It was a very good committee.

Sherwin: Now, everybody was aware of the fact that this was a destabilizing step.

Bethe: Yes.

Sherwin: How did that step get taken, given the awareness? Were you presented with MIRV?

Bethe: We were presented with MIRV among many other developments. We wrote a position paper against it. But we didn’t make it terribly strong because at the time, our main concern was ABM [anti-ballistic missile]. And ABM, we finally won.

Sherwin: Right.

Bethe: And some of the military designers presented MIRV to us as an excellent way to overcome ABM. Now this was, of course, dishonest, but there was something in that.

Sherwin: What was dishonest about it?

Bethe: That they really didn’t want it to overcome ABM, but they wanted it to increase.

Sherwin: I see. I thought they were giving you an argument why ABM was no good. But on the contrary –

Bethe: No, on the contrary.

Sherwin: Okay.

Bethe: What they really wanted was to multiply our offensive capability, and that’s the sense in which it was accepted.

Sherwin: Now, where did this idea come from, for MIRVing? Was that something like the H-bomb which had always been a possibility?

Bethe: I don’t know.

Sherwin: Okay.

Bethe: I don’t know who invented it. It was among the members of our subcommittee. The one most familiar was Richard Latter of the Rand Corporation. It may have already made it in the Rand Corporation or anywhere else. Presumably in one of the development laboratories which developed the missiles. I don’t know, but you can probably find out.