@randahl so the US has two hospital ships the USNS Mercy and the Comfort both with about 1000 Beds all told. This is 10 times the capacity of Greenland's own hospital facilities.
For a lot of maladies Greenland's people are sent to mainland Denmark far away from friends and relatives and referred to the Rigshospitalet.
So while, for US citizens picking up the bill, this might seem questionable, as a hearts and minds exercise it may not be that stupid.
I guess the real question is, what happens when the orange one gets bored or offended or starts a war with a country with some military capability. Will Denmark suddenly find itself having to ship 1K patients back to Europe?