During the Second World War, from 1939 to 1945 Werner Heisenberg was drafted to work on the German Uranium Project . This was aiming at a nuclear reactor, and did not result in any nuclear weapons, possibly because Heisenberg did not want it to. Some historians assume that there was a race between the minute German Uranium project and the huge American Manhattan project. Hans A. Bethe, the director of the theory division of the Manhattan project at Los Alamos, said this was not true. Edward Teller, the father of the American hydrogen bomb, said that Heisenberg sabotaged the German project.