On September 1, 1939, Hitler invaded Poland from the west; two days later, France and Britain declared war on Germany, beginning World War II. On September 17, Soviet troops invaded Poland from the east.
- Germany paying large amounts of war reperations from WW1. - Imperical expansion of Italy, Japan, as well as other nations that soon conflicted with each other's interests - the great depression that allowed dictatorships to arise in countries with new-fangled democratic governments. - disgruntled allied and axis powers that lost land due to the treaty of Versailles.
