The answers are economic, Political, and natural disasters
I'm not sure of his name, but it might have been Darius. If you want more info, search 'Gordian Knot'. There was supposedly a prophecy at the time stating that whoever could untie this immensely complicated knot that tied the king's horse yolk to his chariot would rule over Persia. When Alexander saw the knot he sliced it in two with his sword instead of trying to untie it. I'm pretty sure Darius (or whatever his name was)
D. Pull troops out of France and russia
