- The rise of nationalism and militarism in Europe after World War I.
- The Treaty of Versailles, which ended World War I, was seen by many Germans as unfair and led to resentment and anger.
- The Great Depression, which began in 1929, caused widespread economic and political instability around the world.
- The rise of Adolf Hitler and the Nazi Party in Germany. Hitler was a charismatic leader who promised to restore Germany's greatness and avenge the Treaty of Versailles.
- The failure of the League of Nations, which was an international organization created after World War I to promote peace and prevent future wars.
- The invasion of Poland by Germany on September 1, 1939, which is considered the official start of World War II.
It's important to note that these are just some of the many factors that led up to World War II. The war was a complex event that was the result of a combination of historical, political, and economic factors.