I try to read when I do get a chance...most of this interests me. Europe, like India, is made up of countries with varying cultures and languages. In India, we call them 'states'! However, the underlying commonality of the culture in each of the respective regions somewhat holds it in bind.
It is an interesting observation though, that some of the most bloodiest conflicts happen between people who have more similarities than differences...it's a strange paradox.
I guess when the differences are small, it is easier to pick them out and enhance them...but when they are vast, everyone's different, and hence, ironically, the same! Lol!
The German culture was the same between Jewish people and other Germans in obvious ways. However, there were vast differences between his avowed religion and Judaism. Hitler spoke hateful canards against Jewish people in the context of his religion in his book, his speeches and to his friends (for example, his repetitions of the canard that the Jews killed Jesus). He moved the debate from emphasis on religious differences to an emphasis on his insistence that Jewish people were of a race and culture foreign to Germans.