Why did Hitler declare war against the Jews?
Actually, Hitler declared war on the Jews after the international Jewish community declared war on Germany in 1933, soon after he was elected as dictator. His hatred of the Jews stemmed both from his own personal prejudices and experiences as a child, and the common hatred of Jews in Germany at the time, which had been directly influenced by Martin Luther, the founder of the Protestant Lutheran Church in Europe, and indirectly influenced by centuries of Christian hatred toward Jews in Europe. It was a long process, not the whims of a single man.
