You (and people like you) are way too bold to allow yourself to speak for "the world" or for "the EU". As a member of the world and the EU, I'll say that I personally never wanted for my taxes to be spent to prolong this war. Moreover, if it turns out, as you suspect, it all can change on a whim of a president of the USA, it logically follows it never in fact was "the world" or "the EU" who decided that in the first place. It definitely wasn't mine decision, and I'm pretty sure it wasn't yours.
In fact, it won't even really be the voting citizens of the USA who make any decisions, because when red/blue splits 50/50 it isn't "tyranny of the majority" anymore, it's tyranny of luck.
I was nowhere close to "speaking for the world". I merely stated an obvious fact - one country chopped off a piece of another and it got off scot-free.
Re: your taxes - it'd be prudent to look beyond short-term effects and consider what different scenarios would lead to in the long-term. The EU had no choice but to help Ukraine to resist. Consider where things would've been now if they didn't.
The EU begrudgingly gives assistance to Ukraine, because the US forces them to