From Albert Einstein, discussing the letter he sent Roosevelt raising the possibility of atomic weapons, “Atom: Einstein, the Man Who Started It All,” Newsweek Magazine (10 March 1947):
Had I known that the Germans would not succeed in producing an atomic bomb, I would not have lifted a finger.
As far as I can determine, the scientists working on the Manhattan Project meant for the weapon to be used against Germany. They were bitterly disappointed that the war with Germany ended before the bomb was ready.
So, according to that quote, Einstein, himself a German refugee, wanted to see his home country of Germany destroyed. How curious.
Einstein loathed the Nazis and the feared consequences if they built the bomb. I doubt he wanted to bomb his home country, but was prepared for that to happen if it meant stopping the Nazis from developing the bomb and using it to win the war. However, as the quote implies, he was also quite fearful of the consequences of any country, including the US, developing the bomb.