The word is antisemitism.

Antisemitism did not contribute to outbreak of World War 2. Hitler invaded Poland in order to seize land, not in order to hunt for Jews.

No. Antisemitism as a political ideology (claiming to explain all the world's problems) dates from the 1870s, and the notion that Jews are evil goes back to the First Crusade at least.

The usual disintinction is between (traditional) religious antisemitism and racial antisemitism. The latter arose after religious toleration was accepted in most European countries and religious antisemitism lost much of its force. Racial antisemitism arose from about 1870 onwards and operates with conspiracy theories.

The word is anti-Semitism, or better antisemitism(as there is no such thing as 'semitism' that Jew baiters are 'anti').