AHC: WI: wank the Sassanids

  Well OTL they did take most of that territory and had enough control over Anatolia to march to join the Avars in besieging Constantinople.  I have read that when Heraclius initially overthrew Phocas in 610 the situation was so bad that he initially considered abandoning most of the east and moving the capital to Syracuse.  It took a lot of persuading by many influential locals, including promises of substantial support, especially financial to get him to stay and wage the long and bitter war that ended with apparent success in 628, only for both exhausted empires to quickly lose most/all of their territory to the Arabs.

  As such if something happens so that Heraclius either decides to give up the east or has an early failure and die then the Sassanids would end up with at least the Levant and Egypt and probably at least eastern Anatolia.  They might even get the west if a deserted Constantinople falls to either them or the Avars.

  How long that empire would last would depend on the circumstances but without the bloodshed, economic strain and loss of prestige with their holy sites being sacked their likely to defeat the initial Arab surge out of Arabia.  In fact both empires maintained allied Arab tribes on the fringes of the Levant/Mesopotamia for a long time before their war and the Sassanids are likely to continue supporting their allies, which could mean a clash with the Muslims prior to Mohamed's death.  Which could even butterfly his success in unifying the peninsula.  There was a lot of unrest after Mohamed's death OTL and it could be some power and bribery could see the Caliphate defeated before it really begins.

  Ironically if the latter survived it could end up more friendly to the Christian tribes in Arabia as their likely to trust the Muslims more than the anti-Christian Sassanids.  The Jews could go either way in this issue as I think the Sassanids were showing them some favour.

  PS  I see while I was writing a long reply Max has made the main point.