We did defend Ukraine to the best of our ability, given that we will not risk an apocalypse or bankruptcy over it. There is a limit to everything. Don't be naive.
>By breaking their promise, the US is encouraging nuclear proliferation throughout the world.
Would you rather have a nuclear war now, instead of mere proliferation?
>But Europe is getting smarter and stronger as the US gets stupider and weaker.
If Europe was smart, they would back a peace plan asap. They are not prepared to win a war with Russia, especially if China sides with Russia.