Why did hitler force on harming jewish people during his rule of germany

Most of the reasons why Hitler hated the Jews are theories and are not proven to be true, yet.

The main reason that Hitler was shown to hate the Jews was because that he blamed them for their failure in WWI. He apparently became depressed after hearing the news that Germany had lost, so he blamed the Jews and said that he felt "stabbed in the back". 

Hitler allowed public schools to teach anti-Semitic learnings, which is discrimination against Jews and also a form of racism. The Jewish also had to have certain seats in transportation marked. Soon after they started to basically mark Jews, many of them were not sold anything. This includes medicine, food, and clothes. Moving into the time of the Holocaust, the Nazis began to send Jews to concentration camps where they were gassed to death.

The "Final Solution" was a plan organized by the Nazi's to eliminate the rest of the Jewish people. The Nazi's used methods of shooting, gassing, starvation, and other ways of killing. There has said to had been over 6 million Jews murdered during the Holocaust. 

To have a bunch of countries to team up, and communicate not let the communist break them apart and take over the world