Since first grabbing headlines in 1954, the revocation of Robert Oppenheimer’s security clearance has remained by far the best-known case of a physicist subjected to the anti-communist fervor of the Red Scare. Though a relatively low-stakes affair in itself, the episode was regarded from the beginning as emblematic of the political dangers physicists courted as they embraced their newly elite status in Cold War America.

Among the accusations that Oppenheimer faced concerning his security reliability, one of the more unusual—and seldom discussed—is that he was susceptible to “coercion.” A key piece of evidence the security review board cited on this point was that another physicist, Edward Condon, had arm-twisted him into recanting testimony he had given in June 1949 against a third physicist, Bernard Peters, in a closed session of the House Un-American Activities Committee (HUAC).

Oppenheimer’s undermining of Bernard Peters

Peters was a Polish Jew who was born in 1910 in the German Empire. An anti-Nazi activist, he was held for a few months at the Dachau concentration camp and soon escaped to the United States, where he eventually became one of Oppenheimer’s graduate students at Berkeley. He received his PhD in 1942 and after World War II found a faculty position at the University of Rochester.

Oppenheimer’s treatment of Peters is detailed in Sam Schweber’s In the Shadow of the Bomb and Kai Bird and Martin Sherwin’s American Prometheus . In broad outlines, HUAC asked Oppenheimer to affirm remarks he made during the war to Los Alamos’s security officer, including that Peters and another of his students, David Bohm, were “truly dangerous” and that Peters was a “crazy person.” Oppenheimer did so, claiming, among other aspersions, that Peters had been a Communist Party member in Germany and had complained that American communists were ineffectual.

Peters himself appeared privately before HUAC the following day and, in an uneventful hearing, denied having ever been a member of the Communist Party in Europe or the US. Although Oppenheimer’s testimony was supposedly confidential, quotes were quickly leaked to the Rochester Times-Union. Distraught at the prospect of losing his job, Peters sought counsel among allies, including Condon, at a symposium on cosmic rays held a couple weeks later in Idaho Springs, Colorado.

Edward Condon’s sympathy and revulsion

Since late 1945, Condon had been director of the National Bureau of Standards (NBS) in Washington, DC. Although his politics were unremarkably liberal, in March 1948 HUAC released a report that sought to tar him as “one of the weakest links in our atomic security,” making insinuations about his advocacy for American–Soviet scientific exchange and other supposedly suspicious “associations.”

The report stoked extensive press coverage, but Condon received strong support from the scientific community, and, with no substantial allegations leveled against him, he remained in his role, albeit under a cloud. Soon after, as younger, more vulnerable scientists were called to Washington to testify, Condon took it on himself to invite them to his residence on the NBS campus to offer advice, lodging, and hospitality. Peters, Bohm, and other students of Oppenheimer were among those guests.

Condon was thus enraged by Oppenheimer’s reported disparagement of Peters and sent him a letter directly from Idaho Springs. He wrote, “I have lost a good deal of sleep trying to figure out how you could have talked this way about a man whom you have known so long and of whom you know so well what a good physicist and good citizen he is. One is tempted to feel that you are so foolish as to think you can buy immunity for yourself by turning informer. … You know very well that once these people decide to go into your own dossier and make it public that it will make the ‘revelations’ that have been made so far look pretty tame.”

In addition, Condon wrote to his wife Emilie back in Washington, speculating that Oppenheimer’s testimony was evidence of a mental breakdown. He worried the situation could have implications for national policy, writing, “If he cracks up it will certainly be a great tragedy. I only hope that he does not drag down too many others with him.” He asked Emilie to conceal the letter “so that it cannot be picked up if the FBI should take to snooping around our house.”

Condon assumed that he remained under scrutiny after his HUAC ordeal. He also understood the explosiveness of his assertions about the mental state and hidden vulnerabilities of Oppenheimer, who was still in good public standing as a high-level government adviser.

Oppenheimer recants

Condon was not the only one to prevail on Oppenheimer. Peters and Oppenheimer’s brother Frank—himself a physicist and target of anti-communism—confronted him in person. Oppenheimer also received letters from the prominent physicists Hans Bethe and Victor Weisskopf, who knew him well and urged him to set things right.

Robert Marshak, another Rochester physicist, told AIP’s Charles Weiner in a 1970 interview that the university stood by Peters from the beginning. He recalled, “Amazingly enough, our rather conservative president at that time, Alan Valentine, really went to bat for Peters. He went to Oppenheimer and challenged him to provide the evidence. If he was unwilling to do so, the university would sue unless Oppie issued a public retraction, which he did. … It was one of Valentine’s finest hours.”

Oppenheimer wrote a letter to the Rochester Democrat and Chronicle that was published on July 6. In it, he attested to Peters’s loyalty but persisted in stating that Peters had “participated in the Communist movement in Germany,” while allowing that he denied being a party member. Oppenheiner neglected to note that Peters’s politics in that period were built around resistance to Nazism. He also reflected more broadly, “Political opinion, no matter how radical or how freely expressed, does not disqualify a scientist for a high career in science; it does not disqualify him as a teacher of science; it does not impugn his integrity nor his honor.”

Notwithstanding such pieties, Oppenheimer’s brother and many of his former students lost their jobs in physics in this period and struggled to find new ones, including Bohm, Rossi Lomanitz, Joseph Weinberg, and Melba Phillips. For Peters’s part, while his university retained and soon promoted him, he experienced frustrations gaining State Department permission to travel abroad, which was important for his work on cosmic rays. In 1951, he accepted a position at the Tata Institute of Fundamental Research in India, working with Homi Bhabha. He then moved to Niels Bohr’s institute in Denmark in 1959 and finished his career as director of the Danish Space Research Institute.

A forgotten bomb explodes

On April 16, 1954, the New York Times carried the latest bombshell headline from Oppenheimer’s security hearing: “DR. OPPENHEIMER CALLED INFORMER: Condon Charged Atom Expert Accused a Fellow Scientist as Red to Gain Immunity.” The Times explained that Oppenheimer was asked about the letter Condon had written five years earlier. It also quoted the “cracks up” line from Condon’s letter to his wife, noting the Washington Star had printed the entire text.

In a 1973 interview with Weiner, Condon remarked that the FBI must have intercepted and copied both letters before they were delivered. On the letter to his wife, he said, “That had to be the result of a genuine theft, because my wife had received it and she was so kind of shocked by it, at the extremity, that she hid it in the bottom of her dresser drawer and may still have it—it’s never been out of our possession.”

Condon’s FBI file reveals he was right to be suspicious. A wiretap, for instance, had caught Condon inviting Peters to his NBS residence in 1948. However, Condon was wrong about how the letters came to the board’s attention. When he left NBS in 1951 to become head of research and development at Corning Glass Works, he evidently forgot he had kept copies of them in the attic. These were discovered by an NBS employee inspecting the house, who gave them to the owner of an electrical shop, who notified Sen. Joseph McCarthy’s notorious investigative committee about them.

In the hearing, the review board sought to pin Oppenheimer down on why he had contradicted his testimony. While Condon’s letters suggested he might have done so under duress, Oppenheimer testified that “the real pressure came from people who were not belligerent at all, but who were regretful,” namely Bethe, Weisskopf, and his brother Frank. He said, “They wrote very, very nice letters saying, this guy was suffering for something because I had done it and he should stay in his job.” It was conscience, not coercion.

The Peters episode was ultimately peripheral to why Oppenheimer lost his clearance, but it was quite typical of how the Red Scare could twist allegiances into knots. Condon told Weiner, “I think what happened, as he saw things happening to me and to his students, he became kind of a frightened man. … I had the great advantage that the axe fell very quickly and I could start praying, but he lived for years in suspense of thinking they might go after him any time. And finally they did.”

Further reading and resources

For more on the Red Scare in academia, see Ellen Schrecker, No Ivory Tower: McCarthyism and the Universities (Oxford University Press, 1986). On physics and the Red Scare, see Jessica Wang, American Science in an Age of Anxiety: Scientists, Anticommunism, and the Cold War (University of North Carolina Press, 1999); and David Kaiser, “The Atomic Secret in Red Hands: American Suspicions of Theoretical Physicists During the Early Cold War,” Representations (2005) 90 (1): 28–60. For further background on Condon, see Thomas Lassman, Edward Condon’s Cooperative Vision: Science, Industry, and Innovation in Modern America (University of Pittsburgh Press, 2018). On the experiences of Oppenheimer’s students, see Shawn Mullet, Little Man: Four Junior Scientists and the Red Scare Experience , PhD dissertation, Harvard University, 2008. Bernard Peters’s papers are at the Niels Bohr Archive in Copenhagen; Condon’s are at the American Philosophical Society in Philadelphia; and Oppenheimer’s are at the Library of Congress in Washington, DC.

William Thomas
American Institute of Physics
wthomas@aip.org

---

Sign up to receive the Weekly Edition and other AIP newsletters by email here .

---