Trump has talked his way into a corner again in saying if we don't get it Russia or China will. Russia and China have made no more claim on Greenland than they have made anywhere else in the Arctic. Denmark and Greenland have said expand your bases and personnel, if you want, as you did in the early Cold War.
Denmark and Greenland have said to Trump, no problem about you using Greenland to boost your security, just it isn't for sale. And you shouldn't take it by force as that would be worse than reckless, it would cause irreparable damage to all the alliances that helped America become what it is.
And what it is the only reason Trump is as powerful as he is. Trump is doing his very best to fuck it up.
If you get more from your research which is relevant it let us know. It could be a positive for a change.