Indeed Russia did do that. Guess what? Not our problem. Also, it does not belay the fact that Ukraine was considered corrupt long before the 2014 Russian coup.
Ukraine has never chosen the US as an ally. Ukraine debated joining NATO, which was a hardline for the Russians. Tensions escalated when the US and UK tried to soft nudge Ukraine into joining. This has been an ongoing issue for over 30 years. Every single US President has avoided declaring Ukraine an outright ally because of what it would mean for war escalations and how deeply unpopular it would be. This is the same reason the US has been very careful speaking on China-Taiwan relations.
The fact you think Russia's invasion has to be justified shows your ignorance of geopolitics and war. It is not the United States business to police Russia. When the US invaded Afghanistan, Iran, Iraq, helped Israel bomb Palestine into the stone age, the Yemen bombings, etc - none of it was "justified". If Russia wants to invade Ukraine and you want to stick up for them, at the very least stop lying about it being for moral reasons. None of you give a fukk about the countries in the Middle East and Africa being torn apart by war for decades. You only care about Ukraine because Putin is the villain the Democrats and media told you to fear. You're a puppet, stop pretending that hand up your ass is comfortable.