It's just how ethno cults are set up. In order to gain the advantage of in-group organization they had to have a threat. So when a Jewish kid starts thinking the White kids aren't so bad, crazy wine aunt Muriel pulls them aside and tells them those White kids are Nazis or whatever people of whatever historical war. But hostility begets hostility and the Jews have always hamstringed themselves by being reliant on other groups to feed themselves. The 109 evictions and genocides of the Jews were a self fulfilling prophesy played out across history by a stupid people without the vision to break the cycle of self destruction dictated by their "religion".