With pressure mounting in the High North, Denmark flipped the switch on Operation Arctic Endurance—a real, live, allied military exercise designed to do more than “train.” It’s about defensive readiness. It’s about permanence. It’s about making sure nobody mistakes Greenland for a bargaining chip.

To me, it also sounds like interposing some additional bodies between the U.S. and seizing Greenland.

It's the same reason Russia doesn't want NATO forces in Ukraine (or other contested countries). If there aren't any NATO forces in an area, you can move your military in without having to worry about engaging any military units from NATO - which escalates any conflict off the charts.

If you start keeping French and German troops in Greenland, even if they're a nominal force that doesn't prevent any military threat, then we can't take Greenland militarily without engaging French and German troops. Which should dispel any illusion that we could just march up and take Greenland without people regarding that as an actual act of war against not just Denmark, but NATO more broadly.