A program about what we've forgotten about history had a short story about how American forces did battle with nazi ( I do not capitalize that word) soldiers six months before we entered the war with the bombing of Pearl Harbor. It seems that we had men stationed in Greenland protecting the cryolite mine there after the nazis invaded Denmark. Since Greenland would have made a delicious place for the bad guys to settle and eventually get into Canada and the US, the same people who refused to have a blackout along the East Coast to prevent U-boats from blowing up freighters there were brilliant enough to try to protect the cryolite mines.
Cryolite is essential in breaking down Bauxite, from which Aluminum is made, or something like that.
So...story goes that we (US) sent Coast Guard ships to find these Germans supposedly hiding away at a new weather station in Greenland. Only they were not to be found. As luck would have it, the soldiers and Coast Guardsmen managed to find a Norwegian fishing boat, boarded it and found the seamen were nazis in disguise who immediately ratted out the location of the weather station. It was Hitler's idea, and probably rightly so, that if they caught the weather in Greenland that would eventually arrive in Europe, they could plot their air strikes and battles better. Makes sense...armies still depend on weather forecasts so they don't end up trying to, oh, invade Russia in winter, stuff like that.
Anyway, cool. They get the fake fishermen who rat out the German guys who are sent packing and we have access to the cryolite mines all to ourselves and our allies.
Only, the supply is limited. It runs out eventually and they have to make fake cryolite to deal with the Bauxite problem. The mines closed down entirely by 1990.
Why I write this is because it is something I never heard about and thought was pretty cool. Next time you grab your Reynolds Wrap, think about Greenland and give them a nod of respect.