What were the causes of world war 2? Do you think the western powers could have prevented the war? Why or why not

Among the causes of World War II were, to a greater extent, the political takeover in 1933 of Germany by Adolf Hitler and his Nazi Party and its aggressive foreign policy, and to a lesser extent, Italian Fascism in the 1920s, and Japanese militarism preceding an invasion of China in the 1930s.