Why Didn't the Nuclear Physicists George Gamow Work on the Manhattan Project? Was it because he was a Soviet Defector?

by HenriettaLeaveIt

In the 1940s, George Gamow was one of the world's leading experts in nuclear physics, and defected to the US in the early 1930s, and he became a naturalized citizen in 1940, but unlike many other European defectors and refugees from Axis countries like Germany and Hungry and Italy, he was not asked to work on the Manhattan Project. Does anyone know why this was?

Was there something about Gamow himself, or was it a more general bias/ exclusion towards former Soviet citizens, even if they had become citizens (considering the A-Bomb was kept secret from the USSR until the Americans dropped it.)

Thanks!

restricteddata

In his autobiography (My World Line) he says that he was refused a security clearance because he had been a colonel in the Red Army when he was 20, and he had told many people this. There were not too many Russians on the Manhattan Project (George Kistiakowsky was one, but he had fled soon after the Bolshevik Revolution). Gamow was not cleared to work on nuclear weapon developments until 1948.