The lands in the middle east changed hands so many times that you had a generation be born and grow into adulthood without having being firmly associated with one empire or the other.

You had the nomadic tribes grow rich from their mercenary work for either empire.

You also had the fact that both Christian and Zoroastrian faiths took huge blows as the true cross was stolen by the Persians and then the Roman army destroyed the most important Zoroastrian fire temple and snuffed out the eternal flame there.

And finally after the Persians were defeated by the Caliphate, you the the Romans, against their well established strategies, gather their forces for a decisive battle, and then make tactical mistakes allowing for defeat.

It was the perfect storm of the right place, at the right time, with rolling nat 20s.