Do you have evidence Trump offered $700 billion?
See: https://freerepublic.com/focus/news/4363168/posts?page=173#173
Speaking of interest on our debt, how much would the daily interest be if we added another $700 billion?
Why buy Greenland when we can already have all the military we want there thanks to our 1951 treaty with Denmark? We used to have more bases there during WWII and the Cold War. Trump could have reactivated those bases and/or built new ones anytime he wanted during his five years in office. He still can. No need to buy the cow when you can get the milk for free.
Offered 700 Billion or not - you make a good point.
The US has militarily protected Greenland since World War II.
We still have Pituffik Space Base (Thule Air Base) and there is no reason why additional peacekeeping forces could not be directed there.