Byzantines would have been able to better solidify their hold on Italy if Belisarius wasn't withdrawen to fight Persia. Khosrau I if he decided not to break the "eternal peace" he could have kept him self busy by battling nomadic raiders, expanding Sassanid holding in Yemen, under taking more buidling projects and strengthing the Empire. If the Byzantines and Perisans stayed at peace they would have fared a lot better against the Muslim invasions of the next century.
My own guess is, if the Persian/Roman war was only deferred, which seems likeliest, the Near East would have been less war torn. Both Empires might have defended it harder, but the Arabs probably would have won, and it would have been a richer conquest for the Arabs.
If Persia and Rome had managed to keep the peace, I'd think the Arabs would be more likely to concentrate on whichever state was weaker at the time. The Arabs might end conquering them both, but Islam would be more diversified from an early stage.
Another wild guess is that the Arabs would have concentrated more on Africa.
Since both the Romans and the Persians made a virtue of religious intolerance, I think the Islamic states might acquire that early, and Dar-el-Islam would have been darker.
The Arabs might end conquering them both, but Islam would be more diversified from an early stage.
Another wild guess is that the Arabs would have concentrated more on Africa.
Since both the Romans and the Persians made a virtue of religious intolerance, I think the Islamic states might acquire that early, and Dar-el-Islam would have been darker.
Both slydesertfox and maidras have very good posts, and are likely to be closer to the right answer than me.
But Rome and Persia were both bound to have crisises and low points, even if not with each other.
Low points? Sure. But you'd be very hard pressed to find anything that's going to bring them to their knees like the war with the Sassanians did. Much less one that brings them both to their knees at the same time.
Since both the Romans and the Persians made a virtue of religious intolerance, I think the Islamic states might acquire that early, and Dar-el-Islam would have been darker.
OH DEAR.
Early Arab racism (which is what it was, not religious intolerance, given non-Arabs were initially all but banned from becoming a Believer) used exactly the tools that the Romans had used to shackle the Jews, but imposed these tools upon Christians and Zoroastrians as well. This racism was replaced in the eighth century when Islamised Iranians seized the commanding heights of the Caliphate and Arab chauvinism morphed into something that could be shared by all Muslims.
The Arab Empire was not a whit more tolerant than the empires that proceeded it, and I'm really not sure where the idea that it was comes from. An over-reaction to European colonial ideas about "barbaric Arabs", perhaps?
That and taking the example of the Emirate come Caliphate of Cordoba and extending it across the entire Arab Empire.