I find historical claims like this not very convincing. 1800 BCE looked very different from today and if people from old civilizations start claiming their land, we would not see any end of wars. Should Italy claim most of Europe because Romans had it under their control?
My point would be analogised to Italy thus: that despite it only having existed since 1946, suggesting that meant Italians have _no_ rights to occupation of that land is rather ludicrous. If it were a Roman Catholic claiming this that would be even closer of an analogue to my view.
