The main causes of World War II was the Treaty of Versailles. It was a document where Italy, Britain, France, and the US wanted Germany to pay for starting world war I. But, Germany did not agree with the terms which were that they had to accept the guilt of starting it, had to pay $6,600 million dollars for the damage in the war, made Germany only have a small army, and land was taken from them. The other major reason was there chancellor, Adolf Hitler. He was angry with the treaty of Versailles and was determined to retaliate from it and rebel. When he was voted Chancellor he immediately started to build up the army. He took his anger out on the Jews,also. He believed they were the cause of them to lose World War I and were poisoning Germany. He treated them badly by putting them in concentration camps and killing them. This didn't sit well with the Allies.