> I know petty much nothing, but I cannot help but feel that knowing the result, any answer is equally explainable. If Greenland ruled the world we would all be discussing some nonsense about how easily sleds glide over ice.

It is true that, no matter what state of the world we observed, we would try to come up with the best explanations we could, but if we use that as a reason to dismiss explanations of the actual state of affairs, we would dismiss any explanation of anything.

> Nevermind that this supposes a geographic explaination--I imagine the author is a geographer. But an economist examines it through economic policy, an anthropologist through culture.. etc. who I am sure all have their own 'obvious and inevitable' justifications.

Sure. Reality is complex. It should be no surprise that many disciplines have relevant contributions to explaining it. The fact that economic and cultural considerations are also relevant to history, is no reason to dismiss geographical considerations.