WI: Alliance between Rome and Bactria

So we know that until the 1st century BC, some form of Greek kingdom (Bactria or Indo-Greeks) existed east of Persia. What if Rome, to attack the Parthians from both sides, decides to ally the Indian Greeks. They have more in common culturally than the Romans or the Greeks with Parthia or India. They can understand themselves mutually, as the Roman ruling class speeks Greek. They can communicate through sea travel, since Rome can use the ports of allied/puppet Egypt to trade with India and Bactria.

It's quite clear that this alliance wouldn't be between equal partners, since the Indian Greeks are on the brink to be conquered by neighboring tribes, whereas the Romans haven't yet arrived at the climax of their power. Though, the Romans could help the Bactrians by sending money (gold) and instructors, so that the Bactrians can build up an army similar to the Roman legions.
 
So we know that until the 1st century BC, some form of Greek kingdom (Bactria or Indo-Greeks) existed east of Persia. What if Rome, to attack the Parthians from both sides, decides to ally the Indian Greeks. They have more in common culturally than the Romans or the Greeks with Parthia or India. They can understand themselves mutually, as the Roman ruling class speeks Greek. They can communicate through sea travel, since Rome can use the ports of allied/puppet Egypt to trade with India and Bactria.

It's quite clear that this alliance wouldn't be between equal partners, since the Indian Greeks are on the brink to be conquered by neighboring tribes, whereas the Romans haven't yet arrived at the climax of their power. Though, the Romans could help the Bactrians by sending money (gold) and instructors, so that the Bactrians can build up an army similar to the Roman legions.

Bactria has no ports, unless I'm thinking of the wrong Hellenic Kingdom. If, and I truly mean if (I doubt anyone would go to the trouble of this, if the Bactrians were doing as badly as it would seem, they'd have little to bring to the table) they ever came to an agreement it would have never been so formal as to establish a hierarchy. The Roman viewed themselves in a higher light than most, or any, but they're not China and the Bactrians are too far off and the relationship to pragmatic for either to talk down to the other.
The Romans wouldn't need them in the first place, if they were banking on them attacking they'd just assume the Bactrians would attack during a moment of weakness regardless of if they'd asked at all.
 
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