It makes sense from His worldview. Ukraine are the weaker ones, the natural losers. He doesn't help losers. There is no further thought or consideration. That territory was always Russia's to take when they were ready.
I think it’s worse: Trump et al want to install a neofeudal system of society whereas Ukraine is fighting for the Westen Democracy kind of system. It’s clear that Trump wants to establish that as a futile endeavor
Nah, they just care about money is all. They look at Ukraine and they don't see a profit to be made, so they demand payment or the withdrawal of aid. Greed plain and simple.
"Weaker" is a function of not just your own strength, but that of your allies. Russia wants Ukraine as a way to hit at Europe.
Ukraine and its allies are a match for Russia and its. Perhaps more so, since Ukraine's allies have limited its use of force. With the US out, Ukraine may be able to exert much more force.
Which is to say Trump's judgment of who is weak is deeply compromised by his belief in single strongmen. This will not go well for him.
Ukraine is limited in its use of American weapons. It can't strike well in Russian territory. The US wanted to keep the conflict from escalating beyond Ukraine's borders.
Europe has similar concerns, but if Ukraine loses American support, they may not be able to afford that. They might gamble on direct strikes on Moscow, or at least make it clear that they can.
Which might end life as we know it. Or it might force Russia to the bargaining table directly with Ukraine. Who knows? Let's find out!