“ Mr. Justice Jackson, the United States prosecutor at Nuremberg, stated: 'If certain acts in violation of treaties are crimes, they are crimes whether the United States does them or whether Germany does them, and we are not prepared to lay down a rule of criminal conduct against others which we would not be willing to have invoked against us.' (International Conference on Military Trials, Dept. State Pub. No. 3880, p. 330.) ”