Great question, but let’s bring it down to Earth so we can see from the perspective of history.
American Indians lived in North America for centuries and knew no other people from other parts of the world. When the first Europeans settled they were from the other side of the ocean – a vast inconceivable distance and place. The Europeans were aliens.
The Europeans started to encroach on native lands, pushing natives back into territories occupied by other natives. War between natives broke out. Eventually war with the descendants of the Europeans broke out. It was a mess. Most Indian tribes did combine, sharing the common enemy: The United States of America.
In terms of the modern world, united we stand, divided we fall. We’re divided.