Honestly, as someone who firmly opposes what Putin did, there were better "historical justifications" for Russia to annex Crimea than for the USA to colonize Greenland, a territory that has never been part of the USA. The idea of invading an ally's territory just to steal its resources is particularly shameful and disgusting.
Denmark would likely low key love to shitcan greenland. They are a massive money drain, welfare state. Their minerals exist but not enough to turn the place net positive to their colonizer.
If Denmark could come "steal" something like the Pine Ridge Reservation in the Dakotas, it would be an imperfect analogy. As long as we could lose it while still saving face, it would be absolutely amazing economically for the USA.
> a territory that has never been part of the USA
Not only has Greenland never been part of the USA, it has been part of Denmark for longer than the USA has even existed.