But there isn't a Native American Republic taking in most of the North American continent is there? And not likely to be.

The basic dynamic involved is that settlers engaged in occupying a foreign country tend to go in for what is now called ethnic cleansing, displacing the original inhabitants insofar as they can. It happened in America, Australia, South Africa, Israel. It happened in Ireland too, most especially in some parts, but alongside the other dynamic of trying to exploit the natives rather than replace them, as in South Africa. That keeps the way open in the long run for some kind of qualified reversal.

It's really nothing to do with any intrinsic difference between the people involved.
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But it's silly people getting hot under the collar about imagining how history might have worked out differently. It's just a game after all. (Mind though in the context of the World Cup, it has to be admitted, the fact that something is "just a game" doesn't stop people getting very hot indeed under the collar, and smashing the furniture at that...)