[quote]Still not nearly enough natives.[/quote]

Um, I think there would definitely be enough. Census data from 1980/81 suggests that there were about 1 million aboriginal Canadians and 6.5 million of the largest Mexican indigenous tribes alone. Taking just those numbers and adding them to the roughly 4 million native Americans in the US (that's accounting both single and multi-racial individuals), that's nearly 12 million people. A sixth of that could fight a war.

[quote]And the US and Canada detests each other. And Mexico is aligned to the Third International and ideologically split from the US and Canada. So a union in North America isn't possible, let alone a union of the native tribes.[/quote]

Understandable, what with the past two wars between Canada and the US. However, those are the governments of each country that hate each other. There are likely large masses of civilians that feel the same way, too, but I doubt the natives of each country do. Why? Because both have suffered in similar ways under their respective governments. They share a common enemy in the oppressive white man, and both share their heritage as the original people of the Americas. The same applies between both of them and the indigenous Mexican tribes.

Remember, it isn't the white/Hispanic populace we're talking about here; it's the natives that have been oppressed. While the warring white man may not be so friendly towards the others around him, the natives would be.

EDIT: Accidentally put 2 million for aborigines instead of 1 million.