The reason the Persia lost was because all they wanted to do was fight and because of that they were losing men. They wanted so much land, They decided they wanted to take Greece to.They Sparta and Athens united to eventually beat Persia. Athens Greece wanted to keep their land. All they wanted to do was fight and get more land but when they were all in the water and because they were all in the water and Persia lost the cause and effect is Darius died after and a effect for Persia effect is they lost lots of men and resources so Persia was weekend.
and that is how the Persia lost the war.