First, I’m not sure where the OP gets the idea that europe would have developed ‘nukes, tanks and airplanes’ and subsequently use them to crush the Amerindians at a later date, considering that most of these inventions required the USA to exist in the first place (directly and indirectly as the case might be). If the european colonisation of the Americas didn’t occur, it’s incredibly hard to say how the world would have developed, since the answer rests entirely on the speculator’s own personal fantasies and prejudices.
I’m quite wary of people who imply that the Amerindians lived in some sort of Eden like/communist/pacifist paradise until the ‘serpentine’ whiteman crashed the party. How were the Amerindians not subject to follies and fantasies of human nature, exactly? And what about the African cheiftans who kickstarted the Atlantic slavetrade…
(Afterall, if you want to play that game, you may as well have a burning hatred of the Romans, the Greeks, the Egyptians, the Carthaginians, the Saxons, the Normans (and so forth), right back to the early humans who possibly forcibly displaced the neanderthals…)
Human history is littered with rival tribes supplanting their neighbours for various reasons. That doesn’t make it morally or ethically right, of course, but we can only effect events in our own time; why this pre-occupation with ‘passing down the guilt’ to each new generation who had nothing to do with, and no control over, the actions of their forebears? We ought to righty condemn stupid, cruel and evil behaviour of people in the past and hold ourselves to a different standard because of it, not to assume the burden of collective self-loathing!
All that said… imagining alternate scenarios can be entertaining. A book based around the ‘world without europe’ theme (read: without the Western bloc) came out a few years ago. Called ‘The Years of Rice and Salt’ and written by Kim Stanley Robinson, a self-identified democratic socialist or somesuch, it envisaged what might’ve happened had the Black Death wiped out 99.9% of europe in the 1300s and begins with Ghenghis Khan’s hordes arriving amongst the eerily deserted villages, towns and cities of Poland. Suffice to say, Christianity becomes a ‘minor cult’ amongst the few white people that remain as slaves to the Moors of Spain…
The book’s politics are inevitably silly, but it’s an interesting read nonetheless.