So what you're saying is that America became a superpower because it had a lot of people who, notably, weren't busy spending their time rebuilding society after a war? That seems like a much more reasonable explanation, honestly.
You said that America became a superpower because it had a lot of people, unlike Canada which had comparatively few people.
To which I added that America was different to the countries in Europe that had large populations as those large populations were busy cleaning up the mess made by several wars that took place during the rise of America.
It stands to reason that if your people are busy cleaning up, they aren't moving you forward. There is only so much time in the day. That's a tremendous advantage America had alongside its large population.
I see; I didn't realize you were talking about European countries. Good points, IMHO.
I would add that much of what was destroyed in Europe was necessary to productive, advanced economic activity - factories and their contents, infrastructure, etc etc. The most valuable human capital (looking at it from a purely economic perspective) - young, able, working age adults - were the soldiers and disproportionately killed. And without functioning economies, they produced much less money to invest in rebuilding and growing.
However, the US population is still ~4x the size of any advanced European economy (Germany has ~80 million).
