[aguaviva]

"Invaded" implies a hostile, or at least forceful takeover.

That's not what happened. In fact its local government reached out to the US and agreed to come under its wing as a de-facto protectorate, which it saw as a preferable alternative to Canadanian/British (and in any case German) intervention.

https://en.wikipedia.org/wiki/Greenland_in_World_War_II

[mytailorisrich]

Ok, they "occupied" Greenland if you prefer although if they didn't have Copenhagen's greenlight it was an invasion. But that's largely semantics and does not address the general point and the fact that the US's interest in Greenland is not new despite Trump being Trump and they were keen to keep it. Even at the time it was not new.