You can't write two paragraphs excusing Russia and then say "I'm not excusing Russia btw."
No country should be able to force 'my way or a military invasion' ultimatum on another non hostile sovereign state. If a government interprets a neighboring country joining a purely defensive treaty out of their own volition (no, Ukraine is not secretly run by the CIA after Maidan) as a hostile act, that only means the nationalism levels went out if control.
I'm normally very critical of the US, but neither them nor NATO can be blamed for this conflict.