The first world war broke out because a citizen from Serbia killed the king of Austria.
As a result these two countries started a war and the other countries joined these two countries and this led to the huge world war .
In this world war German was totally crippled and treated like slaves because it lost the war.
So as a revenge Adolf Hitler and Benito Mussolini injected ideas of rationalism into the people of German and prepared them to hold a war against the British
These were the reasons for the 2 world wars
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