High income, stable economies, with a distance, much resources, though small populations compared to great powers. Canada even announced they will raise immigration quota to(or for, forgot) 450,000 to meet 100 million population mark by the end of century so it can compete around Arctic with Russia.
(where is Brianwl when you need him)
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If a game is around long enough, people will find the most efficient way to play it and start playing it like robots