WWII

Going into WWII, Germany was really mad because after WWI, they had demilitarize, they had to take blame for the war, they had to pay a bunch of reparations, and they had to cut back on land.  So they were really mad.  They basically grew their army way bigger than it was in WWI, they gained a ton of land, and they didn't take blame for the war - they blamed the Jews because since their economy was so poor, and it was the stereotype that Jews always worked in banks, that they assumed the Jews were purposely ruining them.  Plus they were in a Great Depression so when Hitler came around, people just wanted a leader.