[hnaccount_rng]

The difference there is method of transportation. Yes bulk transport was possible, but only by sea not by caravan. And even then it’s relatively short distances. Which would imply that India should have been “shielded” by the continued existence of the eastern Roman Empire.

And yes definitely there were trade networks. But they consisted of relatively few but high value goods. Most of which populations could do without. However there is the point that cities formed around goods that were traded. So I’m no longer as certain that there is no correlation