Russia and Ukraine

[The Architect Of Fate]

Before the war started, it was universally acknowledged that Ukraine was one of the most corrupt countries in Europe.

Yup and Russia was more corrupt and Ukraine's culture of corruption is largely a product of Russia's culture of corruption spreading to its neighbors 

https://www.aljazeera.com/news/2022/6/15...in-ukraine

It has banned at least 10 opposition parties from standing in elections and made large parts of its population into second class citizens. 

Those were not opposition parties those were Russian-backed parties that were there to drag Ukraine back under Russia's influence and no banning those parties did not make anyone a second-class citizen. Now contrast that with Russia which is ruled by a group of unelected oligarchs and elections are a sham and Putin is essentially the Tzar in all but name, And you want to whine about Ukraine banning some Russian puppets.  

https://www.aljazeera.com/opinions/2022/...ia-parties

By your standards, the US should sanction it and refuse to provide any economic or military aid.

Nope, the only standard he needs is Russia invaded Ukraine. That alone justifies helping them....

The US is not authoritarian because it supports someone else's fight against authoritarianism. If it is doing that somewhere, that's good.

The US is not an authoritarian state  period. It's not great but it's not authoritarian and in this fight, it certainly is not authoritarian.