What America got, by being the heavyweight in NATO, was the greatest economy the world has ever seen. America got rich by selling Europe a nuclear umbrella, which kept the peace, and let Europe go cheap on defense and long on developing their own economies in tandem. The USD as global reserve currency means the world loans money to the US at the lowest possible interest rate; the US extended that credit to its businesses and education system and infrastructure.
What America loses by gaining Greenland is that worldwide market and those close defense relationships forming a common bloc. The US dollar stops being the reserve currency; America's cheap credit line dries up. American soft power in Europe is gone, and Europe aligns itself with China or Russia for stability, and becomes an American adversary. All so you can have, what, a bunch of melting glaciers?
What America loses by gaining Greenland is that worldwide market and those close defense relationships forming a common bloc. The US dollar stops being the reserve currency; America's cheap credit line dries up. American soft power in Europe is gone, and Europe aligns itself with China or Russia for stability, and becomes an American adversary. All so you can have, what, a bunch of melting glaciers?