Though I understand you compare the history of the US with this situation, I don't believe they are comparable at all. Regarding US/Western World, for sure not everything is hunky-dory to state the least. In the case of Ukraine, I believe the US/western (and part of the eastern) world do what they must do. Ukraine asks for help, and they get the help that can be given. I would even think, when Ukraine wouldn't have asked for support, they would not have gotten any, ie the weapons I mean, as well as the sanctions. Interestingly, the Ukrainian government thinks the 'western' world is like a bunch of pussies, not giving him all the support he is asking for.

Putin and the danger. We disagree on this one. If Putin is allowed to do whatever in Ukraine, ie Ukraine giving in to the demands of Putin and subsequently will execute whatever his mid/longer-term plan is for Ukraine, he will pick his next target knowing he can continue to extend his borders/influence with force without repercussions. It also seems Ukraine peeps don't want to capitulate and added to that something like 100k individuals from outside Ukraine arrived in Ukraine to pick the battle, I suppose as volunteers. No US or western government is involved in this.

Though I only know one person in Ukraine and I know his opinion, I believe most of the Ukrainian people share his opinion: They don't want the Russian army in their country. I believe most of them want to live in peace and harmony in their own free country whilst they don't care about the roots being Ukrainian or Russian. And that is what they are fighting for.