1. Treaty of Versailles and the rise of nationalism:
- The harsh terms imposed on Germany after World War I, particularly the Treaty of Versailles, created resentment and a desire for revenge among many Germans.
- Nationalism and militarism gained momentum in Germany under Adolf Hitler, who came to power in 1933 and pursued aggressive expansionist policies.
2. Failure of the League of Nations:
- The League of Nations, an international organization established after World War I to promote peace and prevent conflicts, proved ineffective in resolving international disputes and preventing aggression.
3. Appeasement and the Munich Agreement:
- In an attempt to avoid war, Britain, France, and Italy adopted a policy of appeasement, making concessions to Germany.
- The Munich Agreement of 1938, which allowed Germany to annex Czechoslovakia's Sudetenland, was a significant example of appeasement but ultimately failed to prevent further German aggression.
4. German territorial expansion:
- Germany began expanding its territory through a series of aggressive actions. It remilitarized the Rhineland in 1936, annexed Austria in 1938 (the Anschluss), and occupied Czechoslovakia in 1939.
5. Non-aggression pact between Germany and the Soviet Union:
- In August 1939, Germany and the Soviet Union signed the Molotov-Ribbentrop Pact, a non-aggression agreement that included secret protocols dividing Eastern Europe between the two powers.
6. Invasion of Poland:
- On September 1, 1939, Germany invaded Poland, marking the beginning of World War II. The invasion triggered declarations of war from Britain and France, which had pledged to defend Poland's independence.
In summary, the combination of factors such as the Treaty of Versailles, the rise of nationalism, the failure of the League of Nations, appeasement, German territorial expansion, and the non-aggression pact between Germany and the Soviet Union, led to the outbreak of World War II in September 1939.