As a American, given what the US is becoming now, also given that Denmark actually has reliable public healthcare and the US canceled it for its own people, Greenland is better off staying with Denmark than with the US. If Russia were to invade, NATO still holds. This is about more oil mining, about Trump appeasing to his oil friends, considering Greenland very likely has a substantial quantity of it.
I don't think any oil execs are interested in this, just like they weren't interested in investing in Venezuela after Maduro's ouster (at least if you believe the Financial Times). Rather these invasions appear to be the pet projects of neo-imperialist advisors in the government who see national growth as a zero sum game, a Starcraft-esque race for a finite set of resources where powerful countries can generate wealt…
Instead he will soon be remembered as the worst US president ever - even after his first term he was already third-worst in most rankings and his second term is orders of magnitude worse.
He will be remembered as the president that destroyed the constitution, destroyed America's formidable power projection, the president that destroyed 60 year long alliances, the president that was unimaginably corrupt. I just hope that American school books will also contain the verdict.