Which is why it's great that Denmark is a NATO member and ally, and why it's great that the U.S. has a military base in Greenland. Awesome! We already have all that - and a few bilateral defense agreements with Denmark as well.

Think maybe some port upgrades might come in handy? Or maybe we might want to look at extracting minerals from Greenland?

In Graph 4 we see that the Danes have roughly doubled their defense spending from 2014-2024. Good for them in finally living up to their treaty obligations after oh, only about 70 years. Better late than never, amirite?

You've handwaved to the idea that Trump must have some different true goal, since his stated goal is so foolhardy. But what could it possibly be that's worth this detriment?

You put much more stock in the Truth Social and press conference rants than I do. I could care less what Trump says in public. What matters is what gets said at the negotiating table, and what actions are taken in real life.

So far, we have this:
businessinsider.com - Trump buy greenland denmark defense spending

And I get that they're required to say "We didn't do this because Cheeto Hitler told us to". I look at the endgame, not the process. If offending some diplomats in tailored suits is what it takes to get other countries to do the right things then let them say Well I never! until the end of time.