I find this stuff so annoying. The way you deal with these people -- abusive snowflakes -- is that you say no. We've appeased and appeased and we get nothing in return, Europe is carrying the entire financial burden for supporting Ukraine (which was a reason to try to keep the US happy) and we just get more tariffs every time Trump has a tantrum.

When people step over the line, tell them to fuck off. This is true in personal relationships and international relations alike. Sometimes there is more nuance but in situations like this it's clear that nothing else works.