Nobody really cared about Iraq or Afghanistan. Sure, it was fashionable to pretend to care, to get on a high horse and tell the USian rabble how immoral they were. But at the same time, people on their high horses also were glad that there was no Saddam Hussein anymore and that the Taliban were beaten (seemingly, back then).
It's different now because the US threatened to invade the Kingdom of Denmark, a supposedly very close ally. Even the threat of doing that is a red line that will be very very hard to uncross after Trump.
The US-Europe military-economic bloc is a strong structure, but of the two Europe is weaker and the participants in Europe stand and fall according to weak ties. Without NATO, it isn't even clear if Poland will have allies. Each of the constituent countries have leaders aware of this. And I'm sure they'll attempt to keep the structure intact. If they fail, they fail but all these dramatic declarations won't have been significant either way. The declarations themselves are just emotional outbursts without even the semblance of even self-interest.
I mean, think about it. If the US has no pathway back to normalcy in relations ("never be trusted") then the cost for all future Presidents to militarily intervene is low. After all, trust is at its minimum value and guaranteed not to rise. If Greenland is core to US interests and Denmark has decided there is no pathway back to normalcy, invasion is on the table for all Presidents, Democratic Party or Republican Party.
Essentially, once you decide that you will never normalize relations, then you're just an adversary: not even a potential future ally. And those who pitch themselves as guaranteed adversaries had better find allies quick.
Just think of the relations the US has with the British. Back in the day, after the independence war, I'm quite sure that there were quite a few people in the US who said something like "never will we have cordial relations with the Kingdom of Britain"...
> I think every American needs to understand this quote:
> > "We will never fucking trust you again."