I think your thinking is short-termist and naive. Naive because:
* Putin will use any pause in fighting that doesn't come with credible security guarantees to rearm and continue (he basically always breaks ceasefires he agrees)
Short-termist because:
* a resurgent Russia and weakened (and alienated) EU will only strengthen China and strategically weaken the US
The USA is powerful but that doesn't mean it can be indifferent to global affairs.
The only plausible rationale for Trump's behaviour is that he doesn't care about liberal democracy, either around the world or at home. If you are a US citizen who doesn't care about their own democracy perhaps that's fine, but if you do believe in the constitution, his behaviour should worry you.
China and Russia are rival powers both seeking some domination over asia (their continent) -- a strong russia will preoccupy china.
As for liberal democracy, only two us presidents in history cared about that for a a brief moment (george bush the latest, woodrow willson the earliest), and that ended in catastrophe.
The US certainly didnt care about democracy in Ukraine when the state department was deciding who should replace the democratically elected leader of ukranine in 2013 (https://www.bbc.co.uk/news/world-europe-26079957 -- you can go find the recording and listen, the media reports are propaganda). Nor did biden care about democracy in UA when he withheld aid in order to have a prosecutor fired (go watch the video of biden, the reporting is propaganda). Nor has the US ever cared about democracy: it does exactly the same across the world -- deposing, blackmailing, threatening democracies all over the world. It even armed al q. in syria just to depose Assad -- the very people who dragged it back into middle eastern wars. Every state which cannot oppose the US is not soverign in the eyes of the US: it must do what it says. Well, now China and Russia are strong enough to do the same.
The US has its sphere of influence: the western hemisphere, europe. And threatens, blackmails, bribes and deposes all of the world to advance its interests. This is the behaviour of a great power -- and Russia has returned to this status.
Unless another great power is willing to contain Russia, there is nothing to be done. Since Russia is not a threat to China or the US at the moment, neither are willing to contain it. And so it goes.
This has very little to do with Trump's personality -- exactly his actions are stated in words by Obama, and every president since Bush: detent with russia, withdrawl from europe, retiring nato, containing china. Trump is just the first to do it. Trump wants peace with rival powers at all costs, hence his "WW3" comments -- the world is now far too risky for the US to impose its will has it had done from 1992 til 2022.
Unfortunately many have grown up in this era and still think an american "deciding" that the world-should-be-some-way is sufficient for it to be that way -- that the US military will be their to impose the will of the western mind. That era is over. It no longer matters what we think -- there's more than one bully in the system.
* Putin will use any pause in fighting that doesn't come with credible security guarantees to rearm and continue (he basically always breaks ceasefires he agrees)
Short-termist because:
* a resurgent Russia and weakened (and alienated) EU will only strengthen China and strategically weaken the US
The USA is powerful but that doesn't mean it can be indifferent to global affairs.
The only plausible rationale for Trump's behaviour is that he doesn't care about liberal democracy, either around the world or at home. If you are a US citizen who doesn't care about their own democracy perhaps that's fine, but if you do believe in the constitution, his behaviour should worry you.