Oppenheimer's 1949 HUAC testimony

J. Robert Oppenheimer’s 1949 testimony before the House Committee on Un-American Activities was at once a performance of composure and an act of disclosure. Summoned on June 7 to answer questions about alleged atomic espionage and Communist activity, he tried to cooperate without appearing defensive; in doing so, he spoke about former students and friends in ways that would soon escape the secrecy of the hearing room. The session left Oppenheimer feeling protected by his public stature, while one of its most damaging passages showed how little control he had over what happened to his words after he spoke them.

The subpoena and the encounter in Princeton

Oppenheimer’s appearance followed an unsettling encounter with two former students, David Bohm and Giovanni Rossi Lomanitz. They explained their predicament while walking with him in Princeton. Oppenheimer had already been subpoenaed himself, and he knew that one member of the committee, Illinois congressman Harold Velde, was a former Federal Bureau of Investigation agent who had worked in Berkeley during the war. His alarm was therefore grounded in specific knowledge, although Lomanitz thought his sudden exclamation that an FBI man was on the committee sounded paranoid.

Oppenheimer later described the encounter as a brief conversation in which he had simply advised the two men to tell the truth. The episode placed him between former students facing political scrutiny and an investigation in which he, too, had become a witness. Bohm would testify in May and again in June, refusing to cooperate on the advice of his lawyer, Clifford Durr, and invoking the First and Fifth Amendments. For the moment, Princeton University publicly supported Bohm. Oppenheimer’s own hearing, by contrast, would show how readily a witness who meant to answer questions could also expose other people to consequences.

A closed session under public pressure

The hearing took place on June 7, 1949, in a closed executive session before six members of the House Committee on Un-American Activities, including Representative Richard Nixon. Oppenheimer ostensibly appeared as chairman of the United States Atomic Energy Commission’s General Advisory Committee. The congressmen, however, were interested not in his advice on nuclear weapons policy but in alleged atomic spies. Apprehensive but determined not to look defensive, he chose not to bring a personal lawyer. Instead, he brought Joseph Volpe and introduced him as the commission’s general counsel.

The questioning lasted two hours. The committee’s counsel began by saying that the committee did not seek to embarrass Oppenheimer, then immediately asked whether he knew that a Communist cell existed among scientists at the Radiation Laboratory. Oppenheimer denied knowing of one. Asked about Joseph Weinberg’s political views, he said he had not known before the war that Weinberg was a Communist and that Weinberg’s expressed views after the war were not Communist-line views.

The hearing’s closed-door setting mattered to what followed. Oppenheimer appears to have assumed that his remarks would remain private, and that assumption shaped the candor with which he discussed people whose political histories could make them vulnerable. The hearing was not simply an inquiry into his own knowledge: its questions drew him into judging the trustworthiness and affiliations of people who had studied or worked with him.

Peters, Chevalier, and the names Oppenheimer gave

The most consequential exchange concerned Bernard Peters, another former student. Asked whether he had told Los Alamos security officers that Peters was dangerous and politically red, Oppenheimer acknowledged that he had made the statement to his security officer, Peer de Silva. He explained that Peters had belonged to the German Communist Party, fought street battles against the Nazis, and been sent to a concentration camp before escaping. Oppenheimer added that Peters had later denounced the Communist Party as insufficiently committed to overthrowing the United States government by force and violence. Asked how he knew of Peters’s earlier membership, Oppenheimer replied that Peters had told him.

That answer revisited a judgment Oppenheimer had made years before, but it also revealed that he had not simply left the question of Peters’s reliability behind. In May, his old friend Samuel Goudsmit had asked whether he still held the same view after discovering Oppenheimer’s wartime statement in Peters’s security file. Oppenheimer had answered, “Just look at him. Can’t you tell he can’t be trusted?” The episode brought his earlier security assessment into the context of a new investigation, where private information and political labels could carry renewed weight.

Oppenheimer also described Haakon Chevalier as a parlor Communist, while saying he did not know whether Chevalier had been a Party member. On the Chevalier affair, he repeated the account he had given the Federal Bureau of Investigation: Chevalier had told him of George Eltenton’s idea for communicating information to the Soviet government, and Oppenheimer had responded in strong terms that Chevalier should have no connection with it. He said Chevalier had not known about the atomic bomb until it was used at Hiroshima. The account was one version of a story whose details differed among the people involved: Chevalier’s memoir described a brief conversation, while Katherine Oppenheimer later recalled that she had been present and had called the proposal treason. In the hearing, Oppenheimer denied that anyone else had approached him for atomic information, without being asked to repeat the separate account he had given during the 1943 investigation.

He identified other former students and acquaintances as well. Oppenheimer confirmed that Lomanitz had been dismissed from the Radiation Laboratory and inducted into the Army because of what he called an unbelievable indiscretion. He acknowledged Weinberg’s friendship with Lomanitz, noted Irving David Fox’s union-organizing activity at the laboratory, and confirmed that Kenneth May was an avowed Communist. In answering where he could, Oppenheimer supplied names and political details; his cooperation was not abstract but attached to particular people and their histories.

A boundary, a favorable impression, and a leak

One question tested the limit of that cooperation. When the committee asked about his brother’s past Party membership, Oppenheimer said he would answer questions put to him but begged the chairman not to press him about his brother, adding that the committee could ask his brother directly. The counsel withdrew the question. The brief exchange distinguished Oppenheimer’s readiness to discuss students and associates from his reluctance to furnish information about a member of his own family.

The session ended with signs that Oppenheimer had impressed his interrogators. Before adjourning, Nixon said he was tremendously impressed and glad Oppenheimer held his position in the government’s program. Volpe was struck by Oppenheimer’s cool performance, recalling that he seemed to have decided to charm the congressmen. All six legislators came down to shake the famous scientist’s hand. Oppenheimer emerged without immediate injury to his standing, and the reception may have strengthened his belief that his public prominence offered a measure of protection.

The hearing’s secrecy proved temporary. The day after Oppenheimer testified, Peters appeared before the committee for about twenty minutes and denied that he had belonged to the Communist Party in Germany or the United States. A week later, Oppenheimer’s closed-session testimony was leaked to the Rochester Times-Union. Its headline singled out the description of Peters as politically red. The report also publicized Oppenheimer’s account of Peters’s escape from Dachau and his earlier denunciation of the American Communist Party. What Oppenheimer had apparently treated as confidential testimony thus became public material about a former student, with consequences beyond the hearing room.

The episode’s central irony lies in the distance between Oppenheimer’s composed appearance and the exposure his testimony produced. He answered questions meant to uncover political affiliations and espionage, while trying to preserve a boundary around his brother and to appear forthcoming to the committee. The legislators’ approving handshakes marked the immediate success of his performance; the leak revealed its limits. In a proceeding he had entered as a famous government adviser, his confidence in the protections of a closed session left others bearing the public consequences of his candor.