Language-based identification of the Other, and allocation of violence accordingly, would appear to be a plan older than pretty much everything except dirt and trilobites.
Judges 12:5-6King James Version (KJV)
5 And the Gileadites took the passages of Jordan before the Ephraimites: and it was so, that when those Ephraimites which were escaped said, Let me go over; that the men of Gilead said unto him, Art thou an Ephraimite? If he said, Nay;
6 Then said they unto him, Say now Shibboleth: and he said Sibboleth: for he could not frame to pronounce it right. Then they took him, and slew him at the passages of Jordan: and there fell at that time of the Ephraimites forty and two thousand.
(That aside, though, I suspect that the bigger difference is not the specific languages at play; but how recently they’ve come into contact. It isn’t a happy story; but two historically important ways of making peace are exterminating the opposition and fighting to a standstill so hopeless that compromising with your enemies is the lesser of two evils. In places where contact has been the rule for enough time, people have likely fought whatever grudges are available either to the end or to sheer exhaustion. When somebody new shows up, this is not the case.)