@icedquinn Russians With Attitude has a fun theory that it's about access to the Arctic: Canada + Greenland would give the US control over the Arctic that's comparable to Russia's, who is currently the only power really situated to exploit it, its natural resources, and a trade route better than the one through the Suez canal that has pirates and fees and Yemeni blockades as concerns.

But, Norway and Canada are already firmly in the US sphere of influence. The suggestion that the US can't exploit their access without a US flag is really a confession of decline.