If I were Ukrainian, then fucking yes. As an American, also yes, because with proper support, Russia won't win and it won't come down to the last Ukrainian. If Mexico invaded the US, killed thousands of Americans, and occupied a bunch, you think just giving some of that up would be acceptable? Fuck that. Not only does sending munitions to Ukraine help them, it both hurts Russia which is great, and boosts the US economy and refreshes our arsenal. War sucks, but since it's happening and we can't stop it, we might as well help the good guys and benefit ourselves.

All of this ignores how past negotiations with Russia have taken place, and they reneged anyway. They can't be trusted to hold up any sort of deal, so fuck em. Best case is that civil unrest ends the war first, but until then, the only good Russian invader is a dead Russian invader.