Couple things you seem to not understand:

• Why is someone who opposes war now, when it's difficult, any different from those who opposed war in 2002? It's not like US foreign policy is any different now than it was back then. Equally evil! Come the fuck on.
• Part of the agreement to reunify Germany was a promise to not move NATO east, this clearly wasn't kept. This is an act of aggression and NATO knows this. Putin is crazy for ignoring the billion reasons to not get into this quagmire but isn't not like there's been no poking the bear.
• Cutting off a modern state from global markets through sanctions is essentially an act of war, and results in countless preventable deaths. They're also ineffective, the US has had sanction regimes against multiple states for decades without resulting in regime changes.

Here's the core of what I think your problem is:

What sort of means of opposing powerful states trying to annex weaker ones are you for?

And I don't have a good answer because the foreign policy apparatus is so monumentally evil that we can't trust it to suddenly have the right motives. What can we do? Well if you look outside this single thread at what the DSAIC does, which is protest, fund labor unions helping people in Ukraine, and support politicians that aren't fucking crazy.

That's all. If you want to be mad at the DSA it's not really skin off my back but I don't see the usefulness here