It is worth mentioning that "the West" promised Putin on several occasions that NATO would not expand to the east, and "we" blew that promise to smithereens (whatever a smithereen is). So the question becomes, knowing that Russia is being led by a megalomaniac former KGB Colonel, was our provocation in this regard sufficient to provoke Putin into his current adventure? Do we blame the bear or the fool who provoked it into attacking? You be the judge.
Second, the merits of the conflict are somewhat murky. Remember that Ukraine (like Palestine) was a made-up country (by Nikita Khruschev), created to add a vote in the U.N. for the old Soviet Union. Historically, it was mostly a part of Russia before NK executed his gambit. Second, parts of Ukraine are mainly ethnic Russian, and the actual people who live there would be content to be brought back into the Russian Federation.
Since we in the West like "democracy" maybe it is OK to let Russia take a few bites out of Ukraine (with popular local support), if what remains is a viable country.