DEAR DR. OPPENHEIMER:

Section 10 of the Atomic Energy Act of 1946 places upon the Atomic Energy Commission the responsibility for assuring that individuals are employed by the Commission only when such employment will not endanger the common defense and security. In addition, Executive Order 10450 of April 27, 1953, requires the suspension of employment of any individual where there exists information indicating that his employment may not be clearly consistent with the interests of the national security.

As a result of additional investigation as to your character, associations, and loyalty, and review of our personnel security file in the light of the requirements of the Atomic Energy Act and the requirements of Executive Order 10450, there has developed considerable question whether your continued employment on Atomic Energy Commission work will endanger the common defense and security and whether such continued employment is clearly consistent with the interests of the national security.

This letter is to advise you of the steps which you may take to assist in the resolution of this question.

The substance of the information which raises the question concerning your eligibility for employment on Atomic Energy Commission work is as follows:

It was reported that in 1940 you were listed as a sponsor of the Friends of the Chinese People, an organization which was characterized in 1944 by the House Committee on Un-American Activities as a Communist-front organization. It was further reported that in 1940 your name was included on a letterhead of the American Committee for Democracy and Intellectual Freedom as a member of its National Executive Committee.

The American Committee for De­ mocracy and Intellectual Freedom was characterized in 1942 by the House Committee on Un-American Activities as a Communist-front which defended Communist teachers, and in 1943 it was characterized as subversive and un-American by a special subcommittee of the House Committee on Appropriations.

It was further reported that in 1938 you were a member of the Western Council of the Consumers Union. The Consumers Union was cited in 1944 by the House Committee on Un­American Activities as a Communist­front headed by the Communist Arthur Kallet. It was further reported that you stated in 1943 that you were not a Communist, but had probably belonged to every Communist-front organization on the West Coast and had signed many petitions in which Communists were interested.

It was reported that in 1943 and previously you were intimately associated with Dr. Jean Tatlock, a member of the Communist party in San Francisco and that Dr. Tatlock was partially responsible for your association with Communist-front groups.

It was reported that your wife, Katherine Puening Oppenheimer, was formerly the wife of Joseph Dallet, a member of the Communist party, who was killed in Spain in 1937 fighting for the Spanish Republican Army. It was further reported that during the period of her association with Joseph Dallet, your wife became a member of the Communist party.

The Communist party has been designated by the Attorney General as a subversive organization which seeks to alter the form of government of the United States by unconstitutional means, within the purview of Executive Order 9835 and Executive Order 10450.

It was further reported that your brother Frank Friedman Oppenheimer became a member of the Communist party in 1936 and has served as a party organizer and as educational director of the Professional Section of the Communist party in Los Angeles County.

It was further reported that your brother’s wife, Jackie Oppenheimer, was a member of the Communist party in 1938; and that in August 1944, Jackie Oppenheimer assisted in the organization of the East Bay branch of the California Labor School. It was further reported that in 1945 Frank and Jackie Oppenheimer were invited to an informal reception at the Russian Consulate, that this invitation was extended by the American-Russian Institute of San Francisco and was for the purpose of introducing famous American scientists to Russian scientists who were delegates to the United Nations Conference on International Organization being held at San Francisco at that time, and that Frank Oppenheimer accepted this in­vitation.

It was further reported that Frank Oppenheimer agreed to give a six­-week course on “The Social Implications of Modern Scientific Development” at the California Labor School, beginning May 9, 1946. The American-Russian Institute of San Francisco and the California Labor School have been cited by the Attorney General as Communist organizations within the purview of Executive Order 9835 and Executive Order 10450.

It was reported that you have associated with members and officials of the Communist party including Isaac Folkoff, Steve Nelson, Rudy Lambert, Kenneth May, Jack Manley, and Thomas Addis.

It was reported that you were a subscriber to the Daily People’s World, a West Coast Communist paper, in 1941 and 1942.

It was reported in 1950 that you stated to an agent of the Federal Bureau of Investigation that you had in the past made contributions to Communist-front organizations, although at the time you did not know of Communist party control or extent of infiltration of these groups. You further stated to an agent of the Federal Bureau of Investigation that some of these contributions were made through Isaac Folkoff, whom you knew to be a leading Communist party functionary, because you had been told that this was the most effective and direct way of helping these groups.

It was reported that you attended a housewarming party at the home of Kenneth and Ruth May on September 20, 1941, for which there was an admission charge for the benefit of The People’s World, and that at this party you were in the company of Joseph W. Weinberg and Clarence Hiskey, who were alleged to be members of the Communist party and to have engaged in espionage on behalf of the Soviet Union.

It was further reported that you informed officials of the United States Department of Justice in 1952 that you had no recollection that you had attended such a party, but that since it would have been in character for you to have attended such a party, you would not deny that you were there.

It was further reported that you attended a closed meeting of the professional section of the Communist party of Alameda County, California, which was held in the latter part of July or early August 1941, at your residence, 10 Kenilworth Court, Berkeley, Calif., for the purpose of hearing an explanation of a change in Communist party policy. It was further reported that you denied that you attended such a meeting and that such a meeting was held in your home.

It was reported that you stated to an agent of the Federal Bureau of Investigation in 1950, that you attended a meeting in 1940 or 1941, which may have taken place at the home of Haakon Chevalier, which was addressed by William Schneiderman, whom you knew to be a leading functionary of the Communist party.

In testimony in 1950 before the California State Senate Committee on Un-American Activities, Haakon Chevalier was identified as a member of the Communist party in the San Francisco area in the early 1940s.

It was reported that you have consistently denied that you have ever been a member of the Communist party. It was further reported that you stated to a representative of the Federal Bureau of Investigation in 1946 that you had a change of mind regarding the policies and politics of the Soviet Union about the time of the signing of the Soviet-German Pact in 1939.

It was further reported that during 1950 you stated to a representative of the Federal Bureau of Investigation that you had never attended a closed meeting of the Communist party; and that at the time of the Russo-Finnish war and the subsequent break between Germany and Russia in 1941, you realized the Communist party infiltration tactics into the alleged anti­Fascist groups and became fed up with the whole thing and lost what little interest you had. It was further reported, however, that:

A. Prior to April 1942, you had contributed $150 per month to the Communist party in the San Francisco area, and that the last such payment was apparently made in April 1942, immediately before your entry into the atomic bomb project.

B. During the period 1942-45 various officials of the Communist party, including Dr. Hannah Peters, organizer of the professional section of the Communist party, Alameda County, California; Bernadette Doyle, Secretary of the Alameda County Communist party; Steve Nelson, David Adelson, Paul Pinsky, Jack Manley, and Katrina Sandow are reported to have made statements indicating that you were then a member of the Communist party; that you could not be active in the party at that time; that your name should be removed from the party mailing list and not mentioned in any way; that you had talked the atomic bomb question over with party members during this period; and that several years prior to 1945 you had told Steve Nelson that the Army was working on an atomic bomb.

C. You state in August of 1943 that you did not want anybody working for you on the Project who was a member of the Communist party, since “one always had a question of divided loyalty” and the discipline of the Communist party was very severe and not compatible with complete loyalty to the Project. You further stated at that time that you were referring only to present membership in the Communist party and not to people who had been members of the party.

You stated further that you knew several individuals then at Los Alamos who had been members of the Communist party. You did not, however, identify such former members of the Communist party to the appropriate authorities.

It was also reported that during the period 1942-45 you were responsible for the employment on the atom bomb project of individuals who were members of the Communist party or closely associated with activities of the Communist party, including Giovanni Rossi Lomanitz, Joseph W. Weinberg, David Bohm, Max Bernard Friedman, and David Hawkins.

In the case of Giovanni Rossi Lomanitz, you urged him to work on the Project, although you stated that you knew he had been very much of a “Red” when he first came to the University of California and that you emphasized to him that he must forego all political activity if he came on to the Project. In August 1943, you protested against the termination of his deferment and requested that he be returned to the Project after his entry into the military service.

It was reported that you stated to representatives of the Federal Bureau of Investigation on September 5, 1946, that you had attended a meeting in the East Bay and a meeting in San Francisco at which there were present persons definitely identified with the Communist party. When asked the purpose of the East Bay meeting and the identity of those in attendance, you declined to answer on the ground that this had no bearing on the matter of interest being discussed.

It was reported that you attended a meeting at the home of Frank Oppenheimer on January 1, 1946, with David Adelson and Paul Pinsky, both of whom were members of the Communist party. It was further reported that you analyzed some material which Pinsky hoped to take up with the Legislative Convention in Sacramento, California.

It was reported in 1946 that you were listed as Vice Chairman on the letterhead of the Independent Citizens Committee of the Arts, Sciences, and Professions, Inc., which has been cited as a Communist-front by the House Committee on Un-American Activities.

It was reported that prior to March 1, 1943, possibly three months prior, Peter Ivanov, Secretary at the Soviet Consulate, San Francisco, approached George Charles Eltenton for the purpose of obtaining information regarding work being done at the Radiation Laboratory for the use of Soviet scientists; that George Charles Eltenton subsequently requested Haakon Chevalier to approach you concerning this matter; that Haakon Chevalier thereupon approached you, either directly or through your brother, Frank Friedman Oppenheimer, in connection with this matter; and that Haakon Chevalier finally advised George Charles Eltenton that there was no chance whatsoever of obtaining the information.

It was further reported that you did not report this episode to the appropriate authorities until several months after its occurrence; that when you initially discussed this matter with the appropriate authorities on August 26, 1943, you did not identify yourself as the person who had been approached, and you refused to identify Haakon Chevalier as the individual who had made the approach on behalf of George Charles Eltenton and that it was not until several months later, when you were ordered by a superior to do so, that you so identified Haakon Chevalier.

It was further reported that upon your return to Berkeley following your separation from the Los Alamos Project, you were visited by the Chevaliers on several occasions; and that your wife was in contact with Haakon and Barbara Chevalier in 1946 and 1947.

It was reported that in 1945, you expressed the view that “there is a reasonable possibility that it (the hydrogen bomb) can be made,” but that the feasibility of the hydrogen bomb did not appear, on theoretical grounds, as certain as the fission bomb appeared certain, on theoretical grounds, when the Los Alamos Laboratory was started; and that in the autumn of 1949 the General Advisory Committee expressed the view that “an imaginative and concerted attack on the problem has a better than even chance of producing the weapon within five years.”

It was further reported that in the autumn of 1949, and subsequently, you strongly opposed the development of the hydrogen bomb: (1) on moral grounds, (2) by claiming that it was not feasible, (3) by claiming that there were insufficient facilities and scientific personnel to carry on the development, and (4) that it was not politically desirable.

It was further reported that even after it was determined, as a matter of national policy, to proceed with development of a hydrogen bomb, you continued to oppose the project and declined to cooperate fully in the project. It was further reported that you departed from your proper role as an adviser to the Commission by causing the distribution, separately and in private, to top personnel at Los Alamos of the majority and minority reports of the General Advisory Committee on development of the hydrogen bomb for the purpose of trying to turn such top personnel against the development of the hydrogen bomb.

It was further reported that you were instrumental in persuading other outstanding scientists not to work on the hydrogen bomb project and that the opposition to the hydrogen bomb of which you are the most experienced, most powerful and most effective member, has definitely slowed down its development.

In view of your access to highly sensitive classified information, and in view of these allegations which, until disproved raise questions as to your veracity, conduct, and even your loyalty, the Commission has no other recourse, in the discharge of its obligations to protect the common defense and security, but to suspend your clearance until the matter has been resolved.

Accordingly, your employment on Atomic Energy Commission work and your eligibility for access to Restricted Data are hereby suspended, effective immediately, pending final determination of this matter.

To assist in the resolution of this matter you have the privilege of appearing before an Atomic Energy Commission Personnel Security Board. To avail yourself of the privileges afforded you under the Atomic Energy Commission hearing procedures you must, within thirty days following receipt of this letter, submit to me, in writing, your reply to the information outlined above and request the opportunity of appearing before the Personnel Security Board.

Should you signify your desire to appear before the Board, you will be notified of the composition of the Board and may challenge any member of it for cause. Such challenge should be submitted to me within seventy­two hours of the receipt of notice of composition of the Board.

If no challenge is raised as to the members of the Board, you will be notified of the date and place of hearing at least forty-eight hours in advance of the date set for hearing. You may be present for the duration of the hearing, may be represented by counsel of your own choosing and present evidence in your own behalf through witnesses, or by documents, or by both.

Should you elect to have a hearing of your case by the Personnel Security Board, the findings of the Board, together with its recommendations regarding your eligibility for employment on Atomic Energy Commission work, in the light of Criteria and Determining Eligibility for Atomic Energy Commission Security Clearance and the requirements of Executive Order 10450, will be submitted to me.

In the event of an adverse decision in your case by the Personnel Security Board, you will have an opportunity to review the record made during your appearance before the board and to request a review of your case by the Commission’s Personnel Security Review Board.

If a written response is not received from you within thirty days it will be assumed that you do not wish to submit any explanation for further consideration. In that event, or should you not advise me in writing of your desire to appear before the Personnel Security Board, a determination in your case will be made by me on the basis of the existing record.

I am enclosing herewith, for your information and guidance, copies of the Criteria and Procedures for Determining Eligibility for Atomic Energy Commission Security Clearance and Executive Order 10450.

This letter has been marked “Confidential” to maintain the privacy of this matter between you and the Atomic Energy Commission. You are not precluded from making such use of this letter as you may consider appropriate.

I have instructed Mr. Wm. Mitchell, whose address is 1901 Constitution Avenue, N.W., Washington, D.C., and whose telephone number is STerling 3-8000, Extension 277, to give you whatever further detailed information you may desire with respect to the procedures to be followed in this matter.

Very truly yours,

K.D. NICHOLS, General Manager

2 Enclosures

1. Criteria & Procedures
2. Executive Order 10450