Putin really messed up when he chose an altogether unsuitable, incompetent puppet to take charge of Ukraine -- setting the stage for these tragic events.
I'm against war and really wish that it didn't take place, however, it seems that Russia was pushed to this action; there was simply no way that Russia was ever going to accept the origin of its civilization (Kievan Rus) being under American auspices.
..Russia was never going to accept NATO (American) bases in Odessa, Sevastopol and other areas of Ukraine; people respond by pointing out that NATO is already on Russia's doorstep vis-a-vis Estonia and Latvia, however, the shared border there is much, much shorter and can be more easily defended in the event of hostilities...
I was mistaken in my naive belief that Russia should simply accept the assurances and Treaty derived guarantees from the Americans. The United States cancelled:
The INF Treaty
The Conventional Forces in Europe Treaty
The Open Sky Treaty...
..So there is no reason why Russia should accept any American guarantees in regard to Ukraine..