Rotblat continued to have strong reservations about the use of science to develop such a devastating weapon. In 1985, he related that, at a private dinner at the Chadwicks' house at Los Alamos in March 1944, he was shocked to hear the director of the Manhattan Project, Major General Leslie R. Groves, Jr., say words to the effect that the real purpose in making the bomb was to subdue the Soviets. Indeed, Groves testified under oath at the 1954 hearing about J. Robert Oppenheimer 's security record that "there was never, from about two weeks from the time I took charge of this project, any illusion on my part but that Russia was our enemy and that the project was conducted on that basis." Despite Groves' testimony, in response to a suggestion by Andrew Brown that Groves' remark may have been made to test Rotblat's loyalty, Barton Bernstein, who had questioned the accuracy of Rotblat's memory, commented in a letter to Brown: "It's an interesting, responsible interpretation, and cannot be dismissed, though I'm not prepared to embrace it."