Autumn Wind wrote:As far as epic wars go, the historical record seems to indicate that the ultimate beneficiary is rarely, if ever, one of the primary belligerants.
Assyria vs. Egypt= Babylon.
Babylon vs. Egypt= Persia
Greeks vs. Persians= Pelloponesian war= Macedon
Romans vs. Persians= Germanic Barbarians
Western Romans vs. Germanic Barbarians= Eastern Romans
Eastern Romans vs. Germanic Barbarians= Persians
Eastern Romans vs. Persians= Rashidun Caliphate
The list goes on.
Napoleon vs. Russians= British
Nazis vs. Soviets= US
Regardless of who starts World War 3, the name of the game would be to deliberately stay out of the game until the 4th quarter, then sweep whoever left standing.
The Greeks vs the Persians was not the same as the Peloponnesian War, you know, though one can make a case for it being part of the aftermath of the Greek victory. The ultimate beneficiary of the Peloponnsian War was Persia, who managed to influence both sides and keep the Greeks from uniting against her.
The Parthians and the Sassanids were never a viable threat to the Roman Empire except locally, in Syria and Armenia. They did not weaken the Empire to the extent that the German barbarians were able to invade in the numbers they did. What allowed a German take-over of the West was a lack or strong government and the fear of usurpation that became a major concern of the Emperors. And a policy, in both the Western and Eastern Empires of admitting German (Gothic) colonists inside the borders.
The Eastern Empire never had the same problems with the Germans that the West had, so no, the Persians did not ultimately benefit from anything like that. What happened at the end of the 6th century was a usurpation, the reigning Emperor Maurice was overthrown by one of his generals, Phocas. Maurice has previously helped the Persian Emperor, Khosrau II, gain his throne and Khosrau now invaded the Empire, conquering much of the Middle East and Egypt. Phocas, meanwhile, proved very unpopular and the Exarch of Africa and his son, both named Heraclius, began a revolt. Heraclius eventually overthrew Phocas and then began a long campaign to drive the Persians out.
I will grant you that this Roman-Persian War did give the emergent Caliphate an opening. I think Islam might have made inroads eventually, however, as even without the Persian War there were deep divisions between Christian sects in the Empire.
What I mean by all this is that it's easy to oversimplify and a little research will reveal not only more information but interesting things, too.