@tadbithuman US did not start it, Russia did.
It's not a proxy war, it's a war of imperial conquest by Russia against Ukraine. With Russia being very clear they do not consider Ukraine a country, Ukrainian a language, and Ukrainians a people.
Putting it in any other terms is furthering Kremlin's propaganda. Please don't do that.
Fantastic resource for anyone who wants to understand what's going on in Ukraine, and why it is happening:
https://www.youtube.com/watch?v=nLfFmYWjHtc&list=PLh9mgdi4rNewfxO7LhBoz_1Mx1MaO6sw_