A couple of lines from this piece with my opinion.
https://www.bbc.co.uk/news/articles/c204vl27n2qo
During the Cold War, the common enemy was the Soviet Union, which included swathes of Eastern Europe.
The US wanted to keep western Europe close, and for it to stay militarily dependent.
Though communism has gone and with it, the attached American paranoia, we still face the same enemy. If Europe were to 'step up' and take on the costs which they surely can (?) then the US and Trump would not be able to use such bully boy tactics.
America has not had it's military presence in Europe as a gesture of solidarity, it's never been a gift. In return they got enormous, influence across the continent, restore national service across all European countries, start picking up the tab and then, let's see how Trump enjoys losing the levers that he currently has. America and it's influence, somehow, has to be removed from Europe.
But also - and this is key - Trump demonstrates not only an antipathy for Europe and an impatience to get the war in Ukraine "done and over", he also displays an affinity for Russia's Vladimir Putin, at a time when Europe considers him an immediate threat to the security and well-being of the whole continent.
This is the biggest problem IMHO, Trump has basically given in to every, Russian demand and in the case of the proposed peace deal, he ruled out two, key, bargaining chips that Ukraine could have used, even before negotiations had started - occupied land and Ukraine's membership of NATO.