Russia armed seperatists inside Ukraine and when Ukraine tried to clear them out, then they attacked a sovereign country by making it as an excuse.

Just imagine this scenario: UK is stronger than USA and arms seperatists inside USA "loyal to crown" and when USA tries to get rid of the pest, UK claims people loyal to the crown getting genocided and attacks USA.

This is EXACTLY what is happening. Like it or not, Ukraine is a sovereign country, they have right to exist, they did not attack any part of Russia whatsoever and they can join whichever organization they want. Soviet Union is collapsed, if current Russian leadership can't handle this fact, they can go fuck themselves.