The League's Spectacular Failures in the 1930s
The economic depression of the 1930s changed everything, making countries more aggressive and desperate. Fascist dictatorships took control in Germany, Italy, and Japan, and these nations were determined to build empires - regardless of what the League thought.
Japan's invasion of Manchuria in 1931 was the first major test the League failed. When the League condemned Japan's actions and supported China, Japan simply walked away from the organisation entirely. This showed the world that the League had no real power to stop determined aggressors.
Italy's brutal invasion of Abyssinia in 1935 was even worse for the League's reputation. Although they officially condemned Italy, Britain and France were secretly negotiating to give Abyssinia to Mussolini anyway! This hypocrisy destroyed any remaining credibility the League had.
Key Point: By 1938, during the Sudeten Crisis, Britain and France were completely ignoring the League and trying appeasement with Hitler instead - proving the organisation was utterly powerless.