As title really.
I didn't want to get involved in a Necro'd thread, but my thoughts for a Nestorian Conquest of Persia would likely involve relying on the Romans for a vast amount of support.
So the question is what PoDs could destabilise the Ummayads enough to enable a Roman reconquest of Syria, alongside the birth of a Nestorian Christian Persian Dynasty, in Mesopotamia with the aim of reconquering Iran.
It doesn't NEED to lead to Roman-Persian SUPER FRIENDS, but extra points if you can reach that point.