What were the 3 main causes of World War 2?

The 3 main causes of World War 2 were as follows:

• Rise of fascism in Europe

• Impact of the Treaty of Versailles following WWI in Germany

• The rise of militarism in Germany and Japan, and the failure of the League of Nations

Out of these the Versaiiles treaty was the most important one as it provided fertile ground for a Nazi takeover of Germany.

For further reading check the following articles:

• World War I
• World War II
• Causes of World War I