I think there would have been a violent uprising. If Germany started slaughtering every single innocent civilian that opposed them (as opposed to mindlessly slaughtering Jews, gypsies, homosexuals, and handicaps) then I'm sure a power such as the US or Russia would have eventually developed nukes and used them on major German things. Eventually world nuclear war would break out, the last remaining countries being those that had nothing to do with WWII (IE South America, Africa).