The Treaty of Versailles is a Youtube opinion now? What do you think caused the rise of the Nazi party? If millions of people can't provide food for their family and a group of outside nations are imposing a "War guilt clause" on your country forcing war reparations, you'll likely feel resent towards them that may culminate in you electing a bloke like Adolf Hitler who created jobs. You can't simply punish millions of people and place them in harsh economic conditions, especially following the 1929 Great Depression. It doesn't work.
This shows you havent watched the documentary i linked.