Another was simple ethnic friction: Jews were an 'outsider' minority group, and thus a target for the resentments of the majority. Jews were present in many countries, and so the prejudice against them was universalized. Ethnic and/or cultural. The majority of European Jews spoke Yiddish (German) which isolated them from Slavic/Hungarian/Romanian local population. Ethnic friction was _base_d on social isolation - Jews didn't marry non-Jews. This was very important in obsolete Eastern European countries during WWII, because family connections were more important than social or political ones. Jews of mixed families had much higher survival rate than orthodoxes. Social friction was _base_d on hundreds years of peasants' slavery. The Jews were always free, sometimes working for masters. When the peasants were liberated in the 19teen Century, they had to challenge Jewish businessmen and they generally failed in Russia and succeded in several places outside Russia.

Perhaps that's one reason why his superiors in WWI rated him as unsuited for any sort of command or leadership role, while commending him as a private or corporal. Hitler's company officer said, apparently truthfully, that Hitler would certainly have been made sergeant and possibly even received a battlefield commission had it not been for the fact that the officer didn't want to lose the services of such a good runner.

Ethnic and/or cultural. The majority of European Jews spoke Yiddish (German) Well, it was a particular sort of German, which probably angered Germans more than if the Jews had spoken Hebrew, which is merely a foreign tongue. In addition to language, many Jews were wildly bearded in a nation of mostly clean-shaven and cropped-head males. They wore funny headgear. Many were shopkeepers in a time of economic stress, runaway inflation followed by a depression. You're not likely to be fond of the person who holds the goods you can't afford to buy. And then of course, the Jews killed Jesus. (I had a problem with this notion, which I heard as a boy from the nuns at school. By my understanding of the story, it was Pontius Pilate for the Romans.) And they lent money at interest when historically that wasn't done by Christians. From Shakespeare on, few European writers had anything good to say about the Jews, with Sir Walter Scott being something of an exception. (I think every boy rooted for Rebecca.) Like gypsies, they just plain had a bad reputation in Europe, and to a lesser extent in America. (That anti-semitism was fairly mild in America, as compared to Europe, is some comfort to me when I think of the country's prewar and even wartime treatment of blacks and Asians.)