Answer:
Germany was absolutely wrecked after the Treaty of Versailles. The US then gave loans to Germany (Weimar Republic). When the Great Depression hit the already struggling economy, unemployment skyrocketed and banknotes became worthless since the bank is printing more and more money. This made the German people furious. Adolf Hitler promised that he can fixed everything, the Nazi Party became popular. After that, Adolf Hitler became chancellor. After President Otto van Hindenburg died, he demanded some land. When he invaded Poland to take the Polish Corridor splitting Germany in two, WW2 sparked.