John Earl Haynes and Harvey Klehr are contributing editors to Washington Decoded, and the authors of many books on the history of American Communism and Soviet espionage.

The relationship of physicist J. Robert Oppenheimer to communism and Soviet espionage has been controversial subject since 1954, when the decision of the Atomic Energy Commission (AEC) to decline renewal of his security clearance put the issue firmly into the public arena. Journalists and historians addressed the issue repeatedly in the decades that followed. Nothing fueled the liberal/left critique of the so-called “national security state” more than the supposed excesses of the US government in the Oppenheimer case, save the cases involving Alger Hiss and the Rosenbergs.[1]

But while the emotional level, even shrillness, of the debate continued, the substance of the argument became increasingly stale and repetitive; there was little new evidence to clarify the ambiguities of the matter. In the last two decades, however, new evidence has emerged that, while not resolving all ambiguities and still leaving a number of details unclear, nonetheless allows confident answers to the question of whether Robert Oppenheimer was a Communist and a spy. It demonstrates that he had, indeed, been a Communist but had not been a spy.

We addressed the issue of Oppenheimer’s involvement in Soviet espionage in “Special Tasks and Sacred Secrets on Soviet Atomic Espionage,” which critiqued and rejected the claims in books written by former KGB officer Pavel Sudoplatov and journalists Jerrold and Leona Schecter that Oppenheimer consciously assisted Soviet espionage and did so in a substantial way. This essay reviews the evidence indicating that Oppenheimer was a secret member of the Communist Party, USA (CPUSA), joining at some point in the late 1930s and actively participating in a secret Party faculty unit at the University of California, Berkeley, in 1939, 1940, and 1941. Secondly, it critiques the conclusion of Oppenheimer biographers Kai Bird and Martin Sherwin that he was never a Communist. Finally, it discusses the evidence indicating that in early 1942 he quietly left the Party, coinciding with, and likely connected to, his formal recruitment into the Manhattan atomic bomb project.[2]

In private conversations with security officers and later in public statements, Oppenheimer admitted his political and financial support for Communist-backed causes in the late 1930s and his social relationship with various Communists. While admitting in 1954 to generous contributions to CPUSA official Isaac Folkoff, he said the funds were not for the CPUSA itself but for various causes supported by the Party such as Spanish Civil War veterans and unionization of farm workers. He explained, “I doubt that it occurred to me that the contributions might be directed to other purposes than those I had intended, or that such purposes might be evil. I did not then regard Communists as dangerous; and some of their declared objectives seemed to me desirable.” He also emphatically denied under oath Party membership or any covert participation in Communist Party meetings or activities.[4]

Even prior to 1999 several sources contradicted Oppenheimer’s denials of direct CPUSA links. In December 1943 FBI listening devices picked up a conversation between Steve Nelson, chief of the CPUSA in the San Francisco Bay area, and Bernadette Doyle,  organizational secretary of the CPUSA’s branch in Alameda County, which included Berkeley where Oppenheimer lived. Nelson and Doyle spoke of both Oppenheimer brothers as CPUSA members, but Nelson mentioned that Robert had become inactive. (That Frank was not characterized similarly along with some other evidence throws doubt on Frank Oppenheimer’s claim that he dropped out of the CPUSA at the end of 1941.)  Nor was this the only time FBI surveillance picked up such incriminating information. Earlier in 1940 a wiretap of the phone of Isaac Folkoff alerted the FBI to a private meeting of senior Communists at Haakon Chevalier’s home. Follow-up FBI surveillance noted that Oppenheimer’s car was parked outside the meeting place. In 1945 the Bureau tapped a meeting of the Executive Committee of the North Oakland Communist Club, at which one Party official, Katrina Sandow, stated that Oppenheimer was a Communist Party member and another official, Jack Manley, boasted that he had been “close to Oppenheimer,” whom he called “one of our men.” Lastly, an undated FBI report, sourced only to informant “T-2” identified Oppenheimer as belonging to a secret Communist Party professional section.[5]