A question I have, that probably can’t be answered, is a scenario in which the Americas aren’t discovered for another few hundred years.
We know there were many great pre-columbian kingdoms and burgeoning empires at the time, so I can only ponder what would happen with a bit more time. When, inevitably, two great pre-columbian empires would wind up sharing a border, and Thucydides trap comes into play, whom would dominate that world so very alien to us?
Essenitally the question is, whenever European explorers arrive, would the Emperor of the Americas sit in Tenochtitlan or Cusco?
Realistically, we are looking at rough equivalents of
very ancient Egypt and Mesopotamia, here. These guys aren't going to become continent-conquerors any time soon. Even getting a real bronze age going would be a huge step for them.
The Aztec hegemony didn't have great long-term prospects, and in-fighting beetween the Nahua states was a given. They were essentially in their warring states phase. I think the Tarascans had a pretty good chance of swooping in and crushing those warring factions after they'd eventually tire each other out.
(Note that while the Aztecs were unusually dickish to their subject peoples, the identification of them as "sadists" is a fundamental misapprehension. The human sacrifices appear to be a ritualised form of population control, since Meso-America had a cycle of overpopulation, drought, and epidemic disease. Seen that way, "mass sacrifice to prevent the end of the world" has a certain
logical truth behind it. A cynical one, to be sure, but it's not like they killed people for the fun of it.)
A Tarascan Empire might plausibly extend to cover an area including roughly the Southern half of modern Mexico, and reaching into the area that is present-day Belize. That is: the Meso-American cultural sphere, plus some expanded periphery.
The Andean cultural complex, meanwhile, looks to have settled into its imperial phase. I see no reason why this wouldn't last for certuries. Any further conquests would presumably be ephemeral; the empire had reached its definitive form. Note that objections such as "they'd need new courts for each dead king" are laughable. Such rituals change when they become impractical. Empires do not fall over that. They'd just symbolically inter each dead ruler into a grand palace where the dead monarchs "rule" for all eternity-- or something like that.
Anyway, the two civilisations would not overlap. There is some evidence of minor sea-trade along the West Coast, and this might plausibly increase. But this would be like interactions between Rome and China (or perhaps Rome and India). Trade goods from afar, the occasional intrepid visitor from distant lands, but no meaningful interactions.
An additional consideration is that without Europeans showing up, the Mississipians will also continue to develop. As I've noted before, one of the best opportunities for a metal-working revolution in the Americas was at the Northern periphery of that cultural sphere, extending into the Great Lakes region.
Final consideration: to keep Europeans away, you need a massive screw-over of all Eurasia. I'm talking
Years of Rice and Salt level stuff here, except you definitely need to fuck over the muslims, too-- otherwise they just show up within two centuries at most. You basically need to go >90% death rate on all Eurasia.
