Russia, as a state, has legitimate concerns around the expansion of NATO. There are thousands of alternate universes where these concerns could have been addressed peacefully. Russia is a great state with a lot of history and heritage and its position in the global pecking order should be solidified.
However, NATO expansion does not give Russia a right to attack a sovereign country and attack civilian population centers with no regard to human life. Russia has been an aggressor in this. No matter where our political sympathies lie, we have to call a spade a spade. Russia started this war.
Russia's war against Ukraine buries its reputation deep, deep into the ground. Putin completely destroys whatever reputation as a "great state" Russia may have had.
NATO doesn’t expand on its own. Sovereign nations seek to join for their own reasons. As a sovereign nation, Ukraine had the ability to seek membership.
Ukraine didn't have the ability to join NATO, it's outlined in its founding documents (Constitution, and the Declaration on the State Sovereignty) that derive from declarations signed between USSR and Ukrainian SSR in 1990 ((Chapter IX. EXTERNAL AND INTERNAL SECURITY): "The Ukrainian SSR solemnly declares its intention to become a permanently neutral state in the future, which does not participate in military blocs and adheres to three non-nuclear principles: not to accept, not to produce, and not to acquire nuclear weapons." [1]
I think it's more about Ukraine having enough resources of gas and oil to replace russia for eu and oh surprise Russia now has control over exact those zones full of resources (south and east).
Nato is not a concern(Finland proves this) because, check, Russia has enough nukes to kill all living beings on earth and still not use all of them
