If sanity were an issue, we should be far more concerned over the many whack-a-doodles with TDS hysteria....
Cool story bro
Back in the real world, Trump indulges in a constant stream of embarrassment and outrages and insults, unlike pretty much any of his predecessors. Obama, Bush 43, Clinton, Bush 41, regardless of party,
none of them deliberately acted like a 2 year old in office.
For the record, there isn't (nor hasn't) been any unwritten principle that colonial or other territories can't be transferred via non-violent transaction.
For the record, buying and selling sovereign properties pretty much stopped being a thing 50-100 years ago. And of course, many of the "sales" you mention were sold by entities that didn't exactly gain the land via peaceful agreement.
And it certainty is not insane to weigh the advantages of owning a territory on a new frontier, soon to be more climate hospitable providing vast claims to arctic oil, gas, fishing rights, and mineral wealth. A value not lost on Russians, the Chinese, and Canada all of whom understands the benefits of owning source of state revenue, taxes, and national income...even if the Trump haters don't.
Re-read my comments about trade, and how bone-headed moves like this drive our own allies into the arms of China and Russia.
Finally, given Denmark's increasingly loose control of Greenland means that military security and force basing may not be available to the US at some point, especially disconcerting in that Greenland itself attempted to facilitate major Chinese involvement with its infrastructure development.
What the f*** are you talking about?
Greenland isn't facing any major military threat. Denmark isn't slacking in its responsibilities in managing Greenland. Greenland is an autonomous territory that
And again: Trump's foreign policy (to the degree it exists at all) is a string of nationalistic, xenophobic, transactional temper tantrums that are largely hostile to our own allies, and friendly to authoritarian leaders. None of that says to Greenland "we want to help you develop your infrastructure." Nor does "I want to buy this autonomous state, and slap the name Trump on it."
Offering to buy Greenland like it's a plot of swamp land is pretty much at the bottom of the list of "intelligent ways to restrain China's international ambitions."
I mean, really. Think about it for a minute. How would you react if Mexico offered to purchase Texas, in an attempt to curtail the international influence of the United States?
On only one point is Trump acting a tad daffy: his cancellation of the trip to Denmark. But that excepted, his position and interest is more than sane - its intriguing and far sighted - which is unusual from a US that normally reacts to events long after the horse has left he barn.
What's truly "daffy" is your implication that Trump is playing 4-dimensional chess, when in reality he is acting like an impetuous child, who throws a temper tantrum at every turn.