See hitler wanted land... He had his allies (Japan being one). He convinced them to help him and take over the world. They mapped out the world saying who got what. Japan made their move to get us in so they could defeat us (pearl harbor). We got mad and went in and kicked a** and won
Racial equality was one of the main struggles in WW2. The Nazis had no interest in promoting racial equality, and they viewed the Jews as a minority race. The United States had to join the war, because there was need to promote democracy.