It is difficult to see what is particularly non-Aryan about the Indus Valley Civilization. - Colin Renfrew

[Supporters of Renfrew’s theory] “have tried to render the Indo-Iranian problem moot. They argue that the Indo-Iranian branch was somehow divided from the main body of Proto-Indo-European before the colonists brought agriculture to the Balkans. Greek and Indic are thus separated by millenniums of linguistic change - despite the close grammatical correspondences between them (... these correspondences probably represent shared innovations from the last stage of PIE).”

Despite Wheeler's comments, it is difficult to see what is particularly non-Aryan about the Indus Valley Civilization, which on this hypothesis would be speaking the Indo-European ancestor of Vedic Sanskrit. Certainly there are elements of continuity from the Indus Civilization onto its aftermath. The main disruption was the ending of urban life, but as Raymond Allchin has emphasized, the rural life of northern India, and what is now Pakistan, carried on little changed.

This area [east Macedonia], although firmly now part of Greece, has sometimes been a marginal one, and may at times have owed allegiance in different directions through a process of boundary displacement. It was indeed occupied in early classical times by Thracian tribes, barbarians who did not speak the Greek language. No doubt they did indeed speak a Thracian language akin to that in what is now Bulgaria, whose origins were suggested earlier.