Quote Originally Posted by Darius
One thing that I know about middle eastern cultures is something that happens when they defeat an enemy army. Their POW's are not released. The defeated enemy army becomes THEIR army. In fact, this has been happening for millenia. It's still happening today even. A formerly Russian army is currently under control of a certain Arab country (can't recall the name) and has been for several years now. The idea that the Parthians might send the Roman survivors to the Far East would only be sensible as it would help deter them from attempting escape...its one hell of a walk back to Rome.
We pretty much posted the same time I will answer this here.

The Parthians weren't Middleastern at all. They were of Scythian stock, who in turn was Indo-European, with weight on European. They adopted part of the Persian culture (such as religion and social structure), the Persians themselves were also Indo-European, though of more eastern stock.
I would not dare go to Iran today and claim them to be arabs...
So we can't argue that that was how things was done, since the Persians didn't pull in prisoners. The Parthians might have done it since they were a relatively small part of the population and the strain of warfare could drain them easily.