You're speaking as if the US started it. They did not. Russia literally invaded Ukraine in the false pretense that they are under the control of a Nazi regime. There is no Nazi regime, barely even a functioning contingent, and certainly nothing out of proportion with the rest of the world's far right representation. If anything, this "proxy war" serves two purposes: 1. To field test new technology and 2. To undercut Russian propaganda. It's apparent to anyone paying attention that Russia is the aggressor, they've vastly oversold their own capability, and their propaganda machine is flailing.

I'm not saying there are no issues within the US that urgently need resolved, but let's be honest with ourselves -- authoritarianism is authoritarianism no matter their lat/long or cultural/economic history, at home and abroad.

Edit: got caught up in my own argument and forgot to mention the obvious third reason: to help the sovereign nation of Ukraine defend itself from invasion.