And don't forget the Greenland threats, those for us Europeans, and in European foreign affairs are a line of non return.
Other administrations will not be able to repair the damage, because what was exposed really is that the US system allows for each administration to destroy and 180 whatever the previous one did.
They can be repaired - but if you think they can't be, then the US should act accordingly which would mean yea go ahead and take over Greenland, withdraw forces from Europe, &c. because as you say they can't be fixed so we might as well do whatever we think we want or need to do - that's the chain of reasoning that this theory of unrepairable relations sends us down.
But we've had challenges and issues before. The US has tried to obtain Greenland in the past. There are plenty of examples of such things throughout history ranging from the Suez Crises, to French withdrawal from NATO, to, well, 2 World Wars caused by Europe, and more and all was forgiven, if not forgotten.
We sometimes think that things in the moment are perhaps more important than they are. The news wants us to believe the world is ending to get clicks. Europe still lets Russian tourists in and houses Russian billionaires and their families despite this existential threat from Russia, as an example.