What three ideas caused WWII

Answer: The Treaty of Versailles ended World War I between Germany and the Allied Powers. Because Germany had lost the war, the treaty was very harsh against Germany ... The treaty required that Germany pay a huge sum of money called reparations.

The immediate cause was Germany invading Poland on September 1, 1939, and Britain and France declaring war on Germany on September 3, 1939. Problems arose in Weimar Germany that experienced strong currents of revanchism after the Treaty of Versailles that concluded its defeat in World War I in 1918.