As pointed out, the harsh reparation terms of the Versailles Treaty created anger and discontent within Germany. Before the war, the newly unified Germany (unified since 1870) had been a rising world power, with a great deal of pride in their culture and a robust, expanding economy. Their military defeat and the terms of the surrender treaty humiliated the country. This paved the way for Hitler and his extremely nationalistic and militaristic supporters to build a movement based on righting the wrongs of the Versailles Treaty and renewing German pride. Hitler wanted to refight World War I, and, once he got into power, World War II was inevitable.
The National Socialists (the Nazi Party) also campaigned on the discontent caused by high unemployment. This unemployment rate directly relates to the Versailles Treaty, which limited the German army to 100,000 soldiers. Previously, the armed forces were much larger. The army had routinely absorbed into its ranks ambitious young men who came from lower class backgrounds and wanted to rise in the world. A soldier was highly respected in German society, and, if he did not die on the battlefield, could count on promotions and earning the income needed to buy a house, marry, and raise a family. When this outlet was cut off, many young men without class privilege found themselves in dead-end jobs with little prestige or with no jobs at all. They were ripe to be recruited into Hitler's army of brownshirts or into the Nazi party in other roles, such as spreading propaganda.
Ironically, the Germans had imposed similarly harsh sanctions on the French and grabbed French territory after their victory in the Franco-Prussian War, so the French and their allies were only responding in kind after World War I. However, it was easy for Hitler and his minions to forget that detail as they stirred up a sense of grievance. It wasn't until after World War II, when the Allies made an effort not to behave too punitively, that a lasting peace was established.