How did the rise of Fascism in Italy lead to the Second World War?

Italy joined the Allies in the First World War with high hopes but she was not satisfied with the territories she gained. Consequently, dictatorship was established there under the leadership of Mussolini. He introduced many reforms and put a new life in the people of Italy by giving military training to them. He wanted to revive the glory of the Old Roman Empire. Italy adopted an aggressive policy and captured Abyssinia and Albania. His policies gave a severe blow to the League of Nations and created an atmosphere of hostility in the world.