In 1519, Cortez arrived in Mexico and meeting very little resistance, took the Aztec Empire by the throat. By the time the Aztecs realized Cortez’s intentions, it was far too late.
In 1532, Pizzaro took the Incan King Hostage after a brief struggle, despite a much larger amount of men at the emporer’s disposal. Pizarro played this for all it was worth and conquered the Incan Empire.
I know this is a big What if but I’ll ask anyway.
If both Empires had realized the Spanish were not to be trusted and had reacted with extreme hositilty the moment they had arrived, would it have been possible for the empires to make the Spanish pay dearly for their conquests, if not survive with their empires intact?
Even if they had reacted right away against the Spanish, European diseases alone would have killed a large percentage of the Aztecs & Incas, which would have made it harder for them to keep their empires together. And remember that the Aztecs had made quite a few enemies among other tribes in the area, who might have been able to take power themselves after the chaos being sowed by the new diseases.
If the aztecs knew somehow that Columbus was coming, they could have made sure that none of people ever got back to spain. As far as Europe knew, there would be nothing between Europe and Japan and the only thing the aztecs would have to deal with would be the occasional dribs and drabs of half-crazy explorers.
But Pedro Cabral discovered the coast of Brazil in 1500. The traditional story is that he was blown off course from a voyage along the coast of Africa, although some now contend that other Portuguese navigators might have visited Brazil even earlier and Cabral knew of this.
If Columbus had never existed, Europeans would certainly have discovered the New World within a few decades anyway. Even if the Americas had been united under a single Empire, it’s unlikely that the natives could have prevented the return of every single explorer for any great length of time.
I agree with RandomLetters that the native empires of the Americas were defeated primarily by disease, rather than by European force of arms.
Did the Aztecs even have the capability of stopping Columbus, even if they’d known he was coming ahead of time, and they wanted to destroy him? Did they even have ships that could have taken them as far as the eastern carribean—to say nothing about actually taking out three ships full of armed men from a civilization a couple of thousand years more technologically advanced than they were?
It appears that knocking off an empire is quicker (and easier, depending) than knocking off a diffused structure.
Note the time difference between taking over the Aztecs and Incas by replacing the top layer around 1500, and the end of fighting with the Apaches in the 1800s.
And on Preview, I agree with Ranchoth about trying to stop Columbus. But if they had known, couldn’t they could have just overwhelmed mainland expeditions with numbers if they decided to?
The Aztecs came very close to doing in Cortez on the Noche Triste (“Sorrowful Night,” as it became known to the conquistadors. He had become virtually besieged within the Aztec capital in Tenochtilan, and managed to escape only by fighting his way out with the loss of two-thirds of his men. The expedition only survived by persuading the Aztec’s enemies in Tlaxcala to become their allies - as well as by the opportune outbreak of smallpox among the Aztecs.
Pizarro suceeded in his conquest of Peru largely because he was fortunate enough to capture the Emperor Atahualpa at the battle of Cajamarca. If the Incas had not been so concerned about ensuring the safety of the Emperor, they probably have besieged the Spanish and eventually starved them out.
The Spanish won partly because of superior technology and partly because of extreme ruthlessnes, bit they were helped by a good deal of luck as well. The Aztecs and the Incas could almost certainly have wiped out the first small expeditions by sheer force of numbers if they devoted all their resources to it. But I think future, larger expeditions would have been likely to have conquered them eventually.