The 1979 Bethe - Kidder Correspondence

introduced by Howard Morland

Hans Bethe, one of the luminaries of 20th Century physics, is the most famous person associated with the 1979 First Amendment case, USA vs The Progressive, et al. At issue was the civil lawsuit initiated by the Department of Energy which, for six months, blocked the publication of an article I wrote titled, "The H-Bomb Secret, to Know How is to Ask Why." In issuing his restraining order in March, the judge cited Dr. Bethe's affidavit in favor of censorship, and noted his prominence in the scientific world.

Dr. Ray Kidder, a nuclear weapon designer at the Livermore Laboratory in California, who soon became the star witness for the defense (i.e., in favor of uncensored publication), believed that Dr. Bethe had been persuaded to sign his affidavit without being given all the relevant information. Kidder proposed that they debate the issue through private correspondence, which they did. Kidder believes that in the tenth and final letter of their correspondence, a cryptic hand-written note, Bethe conceded his point.

The existence of this correspondence was unknown to the outside world until Kidder revealed it to me in the spring of 1999. (Some of the letters had been shared with defense lawyers in The Progressive case, but they were never submitted to the court and therefore do not appear in the case record.) At my request, Kidder had the classified items declassified, a task which was completed on May 1, 2001. It was then discovered that the unclassified letters, stored separately, had been mis-filed and apparently lost, until they were eventually located in September of 2002. For the benefit of scholars interested in the case, the complete set of letters, numbered one through ten, is posted here for the first time.

Kidder's first letter and one of its eight enclosures, or exhibits, were classified secret, as were one of Bethe's and one of Kidder's subsequent letters. The other seven letters were unclassified and were exchanged by ordinary mail between Kidder's Livermore office and Bethe's office at Cornell University in Ithica, New York. Because Cornell has no facility for handling classified mail, the classified letters had to be exchanged while Bethe was visiting various government facilities around the country. The formerly classified letters are noted as such.

Letter #1, with Exhibit #4
[Note: Classified Secret, Declassified May 1, 2001]

April 3, 1979

Professor Hans A. Bethe
c/o Mr. Duane C. Sewell
Assistant Secretary for Defense Programs
Department of Energy
Washington, D.C., 20545

Dear Professor Bethe:

In accordance with our telephone conversation of April 2, I am enclosing copies of several documents that I believe contain information that bears directly and importantly on the case concerning the Morland article that the Progressive Magazine is seeking to publish. I am very pleased that you have consented to receive these documents for your information.

Four of these documents derive from the 1976 disclosures of Soviet physicist L.I. Rudakov. The disclosure itself is described in the September 1976 issue of the magazine LASER FOCUS [ref #1] under the heading "Soviet fusion pellet is said to convert e-beam energy to thermal x radiation." It goes on to say:

This news article discloses the method of the radiation implosion and suggests that this approach may have been known to U.S. scientists but was not discussed in public, i.e., it was classified. The enclosed copy of an article in the 1977 Annual Progress Report of the Institute of Laser Engineering of Osaka, Japan, entitled "Deflagration Waves Supported by Thermal Radiation" [ref #2] references Rudakov's paper, and shows that the Japanese fully and quantitatively understood the principle of the radiation implosion he had disclosed.

The October 8, 1976, article in the magazine SCIENCE entitled "Thermonuclear Fusion: U.S. Puts Wraps on Latest Soviet Work" [ref #3] states in part:

The SCIENCE article establishes that the Rudakov disclosure was classified in the U.S., that it was widely discussed by an international group of scientists (at a Gordon Research Conference), and states explicitly that this esoteric science is related to the H-bomb. (This point could be very effectively impressed upon the court if the article's author William D. Metz, and Dr. Alfred Wong of UCLA, were called as defense witnesses.)

The fourth document deriving (probably) from the Rudakov disclosure of 1976 is the letter of November 2, 1977, from the Chief Classification Officer at LLL, Arthur D. Thomas, to the Director of the Division of Classification of the DoE, John A. Griffin). [ref #4] This letter discloses the fact that scientists in Germany were familiar with the principle of radiation implosion, as were scientists in Japan and possibly Canada and Italy as well. It also shows that the classification people were themselves beginning to seriously doubt the wisdom of continuing to classify the radiation implosion concept that was being openly discussed in international scientific circles.

These four documents together prove beyond any doubt that the principle of the radiation implosion has not been a "secret," in any reasonable definition of the word secret, since mid-1976. They also prove that it was (and is) widely known that the principle of the radiation implosion is classified by the DoE, and that it is related to the H-bomb.

It is also well known that fission bombs are imploded by high explosive (HE), and therefore that the radiation implosion must be used to implode something other than the fission primary, i.e., the fusion secondary. (See Teller's Encyclopedia Americana Article.) [ref #5]

It is also known, for example, that India s Atomic Energy Establishment has kept abreast of developments in inertial confinement fusion. (See copy of a reprint request from the Bhabha Atomic Research Center [ref #6], one of many I have received from India for articles dealing with the physics of ICF implosions.) Is it reasonable to suppose that a staff of Indian nuclear physicists, known to be interested in thermonuclear implosion physics, would not have followed these articles in LASER FOCUS and SCIENCE and understood the stated conclusions? I think not.

Another issue to which I have directed my attention is the Affidavit of Jack W. Rosengren [ref #7] which I find to be misleading and, in part, factually wrong. The Rosengren Affidavit has panicked people by suggesting that the Morland article goes a long way toward identifying "the particular design used in the thermonuclear weapons in the U.S. stockpile." Of course, it does not. U. S. strategic nuclear weapons employ the principle of radiation implosion to be sure, but there the similarity ends. The fusion secondary illustrated schematically in the Morland article is more likely to mislead than enlighten the would-be H-bomb designer for a number of important reasons. (An example of the "panic" referred to above is afforded by the fact that Dr. Theodore A. Postol of the Argonne National Laboratory got John Griffin out of bed at midnight on a weekend to express his concern about the implications of the Rosengren Affidavit.)

I believe that the thrust of Inertial Confinement Fusion (ICF) research made it inevitable that the "secret" would come out. An early indication of the classification problems that would be raised by ICF is provided by Sam Goudsmit's editorial "Secrecy Again" in the Physical Review Letters of January 1, 1973. [ref #8] Even without ICF it would come out eventually, but ICF accelerated the process. The DoE failed to appreciate this evolution, arid now finds itself in the untenable position of continuing to classify concepts that have become common knowledge to a large number of scientists throughout the world.

On the positive side, there are two advantages of declassifying the radiation implosion principle and the fact that this principle is used in H-bombs. The first is that the illusion of secrecy provides a false sense of security. If it were understood that the only real limitation on the spread of nuclear weapons is the availability of fissile materials, more emphasis would be placed on international control of these materials and nonproliferation would be helped rather than hurt. The second advantage is that progress in the field of ICF would be accelerated. While it is true that it is yet to be learned whether ICF will ever be a practical source of energy, it should not be unnecessarily impeded. It might work.

The facts firmly support the conclusion that there is little if any secret left; certainly not enough to damage the nation by disclosure, and certainly not enough to justify the Draconian measure of "prior restraint" for the first time in our history. I also note that none of this evidence supporting the "no secret" conclusion depends on the Morland article or how he may have obtained his information. Whether Morland did or did not rely wholly on unclassified sources is therefore not a crucial issue.

After considering this material, I hope you will convey to Jeremy Stone your views. I fear that the F.A.S. may be engaged in an ill-informed attempt to salvage what I believe is a lost cause.

Reference List [Note: these items are later called exhibits]

1. The News in Focus, LASER FOCUS, September 1976, p. 12.

2. Annual Progress Report on Laser Fusion Program 1977, Institute of Laser Engineering, Osaka University, Japan, pp. 110-112.

3. SCIENCE 1914, October 8, 1976, p. 166.

*4. COK-77-160. Letter (SRD) from Arthur D. Thomas to John A. Griffin, November 2, 1977.

5. Article entitled Hydrogen Bomb by Edward Teller in the Encyclopedia Americana, Vol. 14, 1976, pp. 654-656.

6. Reprint request card from H. C. Pant, Laser Section, Bhabha Atomic Research Center, Bombay, India.

7. Affidavit of Jack W. Rosengren, March 13, 1979.

8. Editorial: Secrecy Again by S. A. Goudsmit, Physical Review Letters 30, January 1, 1973.

*Document COK-77-160 is not enclosed with this letter. It is to be made available to Professor Bethe by Mr. Sewell at DoE Headquarters in Washington.

[Note: COK-77-160, exhibit #4, was declassified on May 1, 2001 and is printed here, below. Several attempts were made to deliver it to Dr. Bethe during the course of this correspondence, but it is unclear from Bethe's letters when he actually first got to read it.]


November 2, 1977

J.A. Griffin
Division of Classification
Washington, D.C. 20545

Dear Jack,

We have heard various anecdotes over the past few years which suggest that the advantages of radiation implosion for ICF targets are not unfamiliar to numerous uncleared scientists, both American and foreign. We recently were provided a very explicit example.

Dr. Ray Kidder of LLL has served for two years on the advisory council of the Max Planck Institut fur Plasmaphysik at Garching near Munich. In this capacity he took part recently In a discussion with Dr. Richard Sigel and Dr. S. Witkowski of the Institut. (Dr. Witkowski is the head of the laser fusion program and Dr. Sigel is his deputy.) Dr. Sigel stated that the two-step process of converting light into soft x-rays and using these x-rays to drive an implosion had the advantage of largely eliminating the problem of dealing with the complex light-plasma interaction. The laser would be focused through holes into a cavity where it would be trapped and converted to x-rays. These x-rays would then uniformly illuminate the target capsule, and effectively drive the implosion (due to the appropriately short wavelength).

Dr. Sigel said he knew this approach was classified. Nevertheless he asked the question raised by these considerations: Should their program for laser fusion concentrate its attention on x-ray implosion, avoid x-ray studies, or what?

Dr. Witkowskl said he felt it was appropriate to study all processes of energy transport that are physically important, neither to stress nor avoid x-ray studies. Dr. Kidder stated that he could not comment on Dr. Sigel s speculations concerning use of x-rays. He did state his belief that the program should study the light-plasma interaction for low, medium, and high-Z elements without prejudice, agreeing with Dr. Witkowski s viewpoint.

This incident is remarkable primarily for its explicit nature. We had heard a few days previously from another source that scientists at the Max Planck Institut were aware of the concept of radiation-driven fusion targets. Based on the increasing emphasis being placed on x-ray transport studies by laser fusion researchers in Japan and Canada, Dr. Kidder believes they are also aware of this concept. (We agree with his assessment.) The Italians also might be ready to investigate radiation implosion targets.

We are conveying this information to you to assist in your planning of both near term and longer range classification policies for ICF. We do not see any obvious best action in light of the currently expanding awareness. However, the passive posture of waiting until after others have started to talk and experiment with a concept before admitting we know about it may not be the most desirable.

The German scientists (for example) apparently have been willing to follow a tacit "gentlemen's agreement" and keep speculations about radiation implosion and its utility in-house for awhile; but when they have results to report, they will make them public. There is the question of what role we should play with regard to influencing the directions taken by uncleared scientists (In the U.S. and elsewhere). Should the policy be to discourage radiation implosion target work and its publication; to continue to classify information we believe is Important to the development of ICF because the concepts are used in weapons; or to consider the best way to declassify the pertinent ICF concepts in an ICF context? Whatever the decision, it is likely to be widely recognized and discussed publicly-ly in a few years.

This leads to a host of related questions. Is there a real advantage in not talking about radiation-driven ICF? What is the benefit and how important is it? Would release of the radiation implosion concept change the decision of current non-nuclear nations?

We are interested in your views and would welcome further discussion of this subject.


Letter #2

April 17, 1979

Dear Dr. Kidder:

Thank you very much for sending me the material in care of Spurgeon Keeny at ACDA. I returned the classified part of it through the office of Dr. Sewell, and retained the unclassified enclosures.

The enclosures did not tell me anything essentially new although I had not seen all of these papers explicitly. After reading this material, my opinion remains entirely unchanged that the Morland article contains far more than has previously been published in the open literature. In a separate letter (which will be sent to you next week) I shall discuss this in detail. Accordingly I stand by my affidavit previously given in The Progressive case.

It has been very helpful to me to have this information, and I thank you for sending it to me.

cc: Dr. D. C. Sewell
Dr. Jeremy Stone, FAS

Letter #3
[Note: Classified Secret, Declassified May 1, 2001]

ITHACA, N.Y. 14653

Dr. Ray Kidder
Lawrence Livermore Laboratory
University of California
P.O. Box 808
Livermore, CA 94550

Dear Dr. Kidder:

In the following I will give you the detailed reaction to the eight enclosures to your letter of April 3. (Actually there were only seven because #4 was not enclosed.) I shall first discuss the odd-numbered enclosures because they seem to me the more relevant.

Exhibit 1, Laser Focus, seems to me the only one which is really important. It tells that Rudakov converted kinetic energy of electrons into energy of soft x-rays which then were used to implode a laser fusion pellet. This report presumably was read by many people internationally. However, no connection is made in this article to H-bombs.

Exhibit 3, from Science, makes such a connection, in a rather vague manner. It however does not talk about the x-ray implosion. If some foreigner puts these two articles together, he might possibly get the idea that x-ray implosion is used in an H-bomb--but he has to be very astute to do so. One of the saving graces may be that the most creative scientists do not usually read very much, and especially do not read semi-scientific journals like Laser Focus and Science. So I would consider it is not clear whether weapons scientists in countries dangerous for proliferation have put these two papers together.

Exhibit 5, Teller's article in the Encyclopedia, is entirely clean as far as I can tell. The paragraph "Construction" mentions only high temperature, not high pressure or density. Likewise, the illustration mentions compression of the primary, but not of the secondary. I do not see how the Teller article could give any useful hint to a would-be proliferator that the secondary has to be compressed, and that this could be done with the X radiation emitted by the primary. In fact, that radiation is never mentioned in Teller's article.

Exhibit 7, I do not see what "factual errors" you discern in the Rosengren affidavit. Perhaps you want to write me about this once more. I can be reached again by classified mail on May 8-10 when I shall be in the Boston area... I shall also be at MIT, and could receive a classified letter through any suitable person at MIT.

Exhibit 2, the Japanese paper, is a scholarly discussion of a radiation supported shock going into a plasma. The possibility of such shocks was known to us at Los Alamos during World War 2, but it did not give any of us, including Edward Teller, the idea of using such shocks to make an H-bomb. So the relation is still quite remote.

Exhibit 4, as already mentioned, is missing.

Exhibit 6, the request by an Indian scientist of the Laser Section of the Bhabha Atomic Center, only shows that the Indians are interested in laser fusion. They may or may not be interested in H-bombs -- Prime Minister Desai has indicated that he is not interested in atomic bombs, but this may of course be revised. Surely I would not draw the conclusion from this request that the Indians have understood how to make an H-bomb.

Exhibit 8, Goudsmit's editorial, is just a genera1ized appeal against secrecy. From the standpoint of an editor of a physics journal this is understandable, but this is hardly a criterion which can be used for declassification.

You mention in your letter that declassification of the presently "Classified Targets" in laser fusion might help the development of laser fusion. I believe that the groups working on laser fusion at Livermore and Los Alamos are very strong and surely can accomplish the goal if this is technically feasible. I do not believe they need help from people outside the classified community. It has bothered me for a long time that the classified targets use similar principles as the H-bomb, and I therefore have never liked the idea of using a laser fusion power plant in a public utility. This clearly is a point which is far down the road, but I don t think declassification of more of laser fusion is necessary or justified at this point.

One argument which persuades me that we should continue to keep the principle of the H-bomb secret is the very long time which it took the French to get to an H-bomb. They exploded their first atomic bombs in 1958, but it was ten years until they got to a thermonuclear test. This was true in spite of their strong desire to develop an H-bomb, and in spite of the obvious competence of the French nuclear scientists.

Clearly some very sophisticated countries, like West Germany and Japan, working on laser fusion, may well get the H-bomb principle. But these two countries have clearly decided not to develop A-bombs, let alone H-bombs. What I am afraid of is the second tier of industrial countries which have not signed the non-proliferation treaty, especially South Africa and Argentina, somewhat less India and Brazil. These countries have competent scientists and some industrial base. But their scientists may not be quite good enough to get the main idea on their own. Serving them this idea on a platter, as the Morland article does, seems to me a very damaging act. It is true that these countries (except India) do not yet have A-bombs, but it is clearly in their capacity to get them. Seeing an easy road to H-bombs can only stimulate them more on to the road to A- and then H-bombs. H-bombs, by their smaller weight for a given yield, will be easier to deliver than A-bombs.

Having read the Morland article and his affidavit to the court, I cannot explain his motives as anything but malice towards the U.S. Publication would serve no useful purpose that I can see. He claims that spies from other countries can find out the same as he has found out, I would disagree: Following our very strange laws of openness, Morland got access to many sensitive installations. Such access clearly would not be given to a citizen of South Africa or Argentina.

cc: Dr. D. C. Sewell

Letter #4

May 1, 1979

Dear Professor Bethe:

Thank you for your letter of April 17 (unclassified) and for your- thoughtful and detailed critique of April 23 (classified) of the points raised and exhibits enclosed in my letter to you of April 3. I am sorry that you were not given the opportunity to read Reference 4 (COK-7 7-160. letter (SRD) from Arthur D. Thomas to John A. Griffin, November 2, 1977), an important document in support of the "no secret" thesis. I was assured that a copy of this document would be made available to you by Mr. Sewell at DoE Headquarters (as was stated in my letter of April 3), but unfortunately it was not.

It is clear that we are not in agreement on a number of points, but I believe that the source of this disagreement is readily identified.

There is no disagreement concerning the content of the published articles (exhibits 1,2,3,5,8) that accompanied my letter, when each is considered independently of the others. The documents speak for themselves.

The disagreement arises as to the likelihood that these documents would be collected together in one place; and as to what might be deduced from them if they were to be considered as a whole. This, of course, depends upon the nature of the person or persons doing the collecting and deducing. We can reach agreement on the significance of these documents only after we have agreed on the probable nature of what I shall term The H-Bomb Study Group of Nation X (HSX).

I believe we must assume that a foreign government seriously interested in informing itself about H-bombs would establish a competent HSX for this purpose that would include physicists experienced in hydrodynamics, nuclear physics, and astrophysics. The services of capable scientists with these skills are both available* and inexpensive. Such an HSX would, among other things, certainly carry out a thorough, systematic, and possibly computerized search of the Inertial Confinement Fusion (ICF) literature. Not to do so would be to disregard what is known to be a source of information that bears a close relationship to nuclear weapons, and would be inconsistent with the assumed competence of the HSX.

The probability that the published articles to which I have drawn your attention would escape such a systematic literature search is nil, in my opinion. Not only would these articles be discovered but they would excite exceptional interest, since they disclose material stated to be classified.

The probability that an HSX, properly constituted as outlined above, would fail to deduce the H-bomb secret upon carefully analyzing the contents of these articles when placed side by side is also nil, in my opinion. These two statements of null probability are the basis of my "no secret" thesis.

On the other hand, remarks contained in your detailed critique of April 23 suggest that you envisage an HSX as consisting either of creative scientists who will fail to read the relevant material in the ICF literature, or of (presumably) uncreative weapons scientists who would not be sufficiently astute to see the significance of this material even if they did read it. This is where we disagree.

If we assume that the H-bomb secret is of such vital importance as is stated in the sworn affidavits of Secretaries Brown, Schlesinger, and Vance, we cannot at the same time assume that a matter of such vital significance will be addressed in a haphazard and amateurish manner by nation X such as you appear to suggest. To use a current idiom, "One can't have it both ways".

It might be argued that even though the secret of the H-bomb may indeed be deducible by a competent HSX, as I believe it is, the publication of the Morland article will encourage nations to take an interest in H-bombs that might not otherwise do so. This argument might have had some merit had not the Government been so quick to validate the contents of Morland's article by means of unclassified affidavits such as Rosengren's. As it is, the world has been notified with much fanfare that the H-bomb secret has been discovered by an individual possessing only an undergraduate degree in economics. This would seem to provide ample encouragement to any nation that does not already know the secret to establish an HSX and find it out for themselves.

Additional comments on specific exhibits:

I am advised that Dr. Rosengren and Dr. William Grayson of DoE have filed an affidavit that attempts to refute my criticism of the original Rosengren affidavit, and I will wait until I have had an opportunity to read their rebuttal before supplying more detailed comments to you in this regard. At that tine I will reply to additional points raised in your letter that cannot be discussed in an unclassified letter such as this.


Letter #5

May 14, 1979

Dear Dr. Kidder:

Thank you for your letter of May 1 which I just received after returning from a prolonged absence.

I think you have correctly identified the source of our disagreement, namely whether the published articles accompanying your letter are considered independently, or collected together.

It is likely that some foreign governments interested in informing themselves of H-bombs would establish a competent HSX. I also agree with your footnote that we only consider those nations X that have the scientific expertise and technology to successfully design and construct a fission bomb.

However, not every nation competent to do so would be seriously interested in informing itself about H-bombs. As you yourself say, on page 2 of your letter, "It might be argued .... that the publication of the Morland article will encourage nations to take an interest in H-bombs that might not otherwise do so." I would go even farther and say that if these governments conclude that H-bombs are feasible for them they might even change their attitude toward nuclear weapons altogether: If they had previously decided not to build nuclear weapons at all, the possibility of going all the way to the H-bomb with its easier deliverability might induce them to go on the path toward nuclear weapons.

You are correct that the attention that has been drawn to the Morland article itself is an incentive for any nation to look at the H-bomb possibility, even if the article is never published. But what should our government do? Should it simply permit the publication of any of the major military secrets, for fear that drawing attention to these articles would aggravate the situation? This would really create an intolerable situation, and would call for some changes of the law, so as to make it more difficult for somebody like Morland to "discover" secret information.

Concerning Reference 4, I believe the letter from Arthur D. Thomas to John A. Griffin was sent to me together with the other documents. However, there was no way for me to tell that this was Reference 4. I read that letter with interest, and in retrospect I can say that it is relevant. But it seems to me that this is in the nature of a slow leak rather than a blow-out as the Morland article would constitute.

Concerning a classified letter to me, I have no plans at present to go to Washington or to Los Alamos. However, I am planning to go to Seattle, Washington. Probably there is no classified mailing address there either, but I shall also go to Hanford, and I am sure there must be a classified address there.

Your letters have greatly clarified your point of view. If it were not for the legal proceedings, we might even come to some agreement on middle ground in the end. But in relation to the lawsuit, I should be happy if you could send a copy of my letter with detailed critique of April 23 to Mr. Munson of LaFollette, Sinykin, Anderson & Munson, as he has requested in his letter of May 9 to me.


Letter #6

June 8, 1979

Dear Professor Bethe:

Thank you for your letter of May 14. I apologize for not being able to answer it more promptly.

You raise two important points in your letter upon which I should like to comment. The first is that "if these governments conclude that H-bombs are feasible for them they might even change their attitude toward nuclear weapons altogether:..." I agree that your conclusion follows from your premise, but it is not clear to me that a government's perception of H-bomb feasibility would be significantly altered by its knowledge of the Morland article.

To achieve a reliable H-bomb capability, a government must face the necessity of carrying out an unpredictable number of nuclear tests, including at least one at high yield. This requirement is importantly different from the acquisition of fission bomb capability, where a single low-yield test, or perhaps even none, will likely suffice. Such an extended multi-shot test series could have disastrous consequences for the government concerned, in terms of world opinion, political and economic sanctions, or even military action.

Contemplation of these possible consequences would powerfully suggest that the advantages of H-bombs over A-bombs (or no bombs) may not be worth the risks that must be taken to acquire them. These political considerations seem to me to be far more significant to any H-bomb decision than is the information contained in Morland's article, particularly since this information cannot be assumed to be reliable.

Your second point is the question: "Should (our government) simply permit the publication of any of the major military secrets, for fear that drawing attention to these articles would aggravate the situation?" Certainly not, if they can be demonstrated to be both "major" and "secret". However in the Progressive case, it seems likely that the secret in question will fail to meet commonly accepted standards of what constitutes a secret, in view of the existing published literature. Should the government lose its case as a result, it clearly would have been preferable to permit publication without comment.

I have deferred sending to you my classified comments concerning your letter of April 23, because I fear that I have missed the opportunity to intercept you at Hanford. Those comments are brief, and not of major importance to our exchange of views. However, I shall try to send them to you if you can provide me, once again, with a suitable address, together with the date when you plan to be there.


Letter #7

June 14, 1979

Dear Dr. Kidder:

Thank you for your letter of June 8. Your arguments that it takes a lot to achieve H-bomb capability are well taken. However, I believe in defense in depth, and would like to preserve the first line of defense, namely secrecy of the principle, as long as that is feasible.

My visit to the Hanford area is still in the future; it will be between July 10 and August 15. I shall be in Seattle for approximately this time, and I shall probably visit the Hanford area at least twice during this period.

I would still be interested in your classified remarks. If you send them to Hanford, please indicate where in Hanford I can look at them. The most convenient for me would be Battelle Seattle Research Center but that may not have a sufficiently cleared repository. Personally, I shall be working with Exxon Nuclear which I imagine does not qualify.


Letter #8

July 20, 1979

Professor Hans A. Bethe
Battelle Seattle Research Center
4000 NE 41st Street
Seattle, Washington 98105

Dear Professor Bethe:

This note is to inform you that my classified comments concerning your letter of April 23 will be available for you to read at the office of

The documents will be available on August 20, the expected date of your visit to Richland, but will also be available during the previous week of August 13-17 in case you decide to move your visit forward, a possibility you mentioned in our telephone conversation of July 20.

Reference 4 will be included with my comments as you have requested.

cc: Kenneth E. Sebrell

Letter #9
[Note: Classified Secret, Declassified May 1, 2001]

July 25, 1979

Professor Hans A. Bethe
c/o Mr. Kenneth Jackson
Director of Safeguards and Security
U.S. Department of Energy
Richland Operations Office
P.O. Box 550
Richland, Washington 99352

Dear Professor Bethe:

Three points remained in your classified letter of April 23 that I could not comment upon in my unclassified letters of May 1 and June 8. I shall now remedy that omission.

With reference to Exhibit 5, the Encyclopedia Americana article on the H-bomb, you state that it "is entirely clean as far as I can tell". I agree that the text is entirely clean but the figures are not. They are properly classified (SRD) according to paragraph 413 of Joint AEC/DoD Nuclear Weapons Classification Guide CG-W-4 which states that

With reference to Exhibit 3, the SCIENCE article, you state correctly that this article "does not talk about the x-ray implosion. It does, however, accurately reference the Rudakov paper in the 20 August issue of the Soviet physics journal JEPT Letters in which the x-ray implosion is described (JETP Letters 24, 182, 1976, copy attached), and thus directs the reader to this explicit source.

Finally, you refer to "the very long time which it took the French to get to an H-Bomb". This fact by itself does not prove that the long delay was due to ignorance of the radiation implosion concept. Many other diverse factors, technological, scientific, and possibly political, may have contributed to the delay. In any event, the French did not have the benefit of the Rudakov disclosure and the publicity that accompanied it, so that their experience is of limited applicability to the present situation.

Reference List:

1. Thermonuclear-neutron Yield from a Plasma Compressed by a Shell, L. I. Rudakov et al., JEPT Letters 24, 182 (1976).

2. COK-77-l60. Letter (SRD) from Arthur D. Thomas to John A. Griffin, November 2, 1977. [Note: This is the same as Exhibit #4, attached to Letter #1]

Letter #10

(Note: An undated, handwritten note on the back of documents being returned to Kidder, presumably soon after July 25, 1979. It refers to the three items mentioned in Kidder's Letter #9: Namely the French H-bomb program and Exhibits 3 and 5 with Letter #1. Kidder believes Bethe is saying here that Exhibit 3, the discussion of radiation implosion in connection with inertial confinement fusion research, and Exhibit 5, the H-bomb diagrams in the Encyclopedia Americana article, did in fact place the H-bomb secret in the public domain several years before The Progressive case.)

Dear Dr. Kidder:

Thanks a lot for the interesting documents. I still disagree with your assessment of the French. On exhibits 3 and 5, you are right.