1930s Germany didn't hate the japanese, despite them being very different from them (appearance, culture). Instead, they hated the German/european jews, who were basically visually indistinguishable.
it was a few that pushed that hatred. Hatred is usually engineered as a distraction for a crime. Usually those committing the crime and pushing the hatred are very close.
Yes. People in close proximity are in competition. When technology makes the whole world your neighbour, you're at war with the whole world.