There is one thing you forget about.
There are two blocs in the world, one of them is liberal, democratic bloc: USA, Europe, Japan.
Another is autocratic: China, Russia, North Korea.
When you give Ukraine to Russia, you lose 25 million people, your enemy gains 25mln people, enemy gains 1mln possible troops, Ukrainian ammo and drone factories and Russia becames USSR again, a powerful country once again.
Its relatively cheap to give arms to Ukrainians, so that NATO has a safe Europe and safe Europe can assist USA when needed. That was Biden politics.
Clearly Donald Trump has another idea, that Europe should pay for its protection, and its understandable as well.
Why is it that the liberal and "democratic" bloc spends the majority of its money fighting against democracy in foreign countries? I don't see China doing that nearly as much as the US or EU.
"Democracy" for me, but not for thee.