canada and denmark used to argue over who owns some small island. things started escalating and denmark sent it's navy there too, lol. i think it was around 2006ish. the us stepped in and basically said "you're both in nato so calm the fuck down, retards" and i think we agreed to share it or something.  anyway, there's no way denmark would ever sell greenland because it grants a massive swath of resource rich arctic ocean territory (canada and denmark were fighting over that island basically because whoever has it gets a few more miles of arctic ocean).
Canada