Sovereign nations get invaded, bombed, and couped all the time. The US is the last country to be chastising another nation for invading another country. We've got armed forces actively fighting in about 100 other countries right now with no declaration of war in any. We're illegally occupying 1/3 of Syria.
Apropos coup: The US backed the coup in Ukraine that put "Yats is the guy" into office undemocratically (not following the Ukrainian constitution). Ukraine did not uphold Minsk II. The US broke the Budapest memorandum. All that happened before Russia invaded in 2022.
So to pull dates from 1200 years ago, but ignore the coup, civil war, broken and never implemented treaties from the last 8 years is some serious bullshit.
Ukraine hasn't been soveriegn since 2014 (maybe 2004 depending on who you ask). Since 2014 the US has been calling the shots - including picking the leaders.
"The world" is no longer dominated by the US and EU. More than half the world's population supports Russia openly, or refuses to condemn them.
The world has changed, and the sooner we in the EU and US accept that, the better it will be for all of us except the 1% in the US.