If the russians are not stopped in Ukraine, then there is no reason to believe that they wouldn't rinse and repeat in Baltic states, Kazakhstan, Moldova, and all other now independent former russian states. Including Alaska[4], should opportunity represent itself.
To truly secure Gorbachevs place in history, world must decisively say no to the russians agressions in Ukraine, and help Ukraine deliver a humiliating defeat to the russians and the dissolution of soviet union reach it's logical conclusion by stripping russia and their dreams off of any status as military, or world power.
[0] https://edition.cnn.com/europe/live-news/russia-ukraine-war-... [1] https://www.bbc.com/news/magazine-26769481 [2] https://www.theweek.co.uk/news/world-news/russia/957367/russ... [3] https://www.atlanticcouncil.org/blogs/ukrainealert/putins-en... [4] https://www.snopes.com/news/2022/03/19/does-russia-want-alas...
Russia has no moral or any other claim over Crimea. Their actions in starving millions of people to death in Crimea in the 20s, the ethnic cleansing by evicting Tartars and Cosacks, replacing them with Russians - these all go to the long term drive of Russian imperial ambitions in the area.
Putin tried to take the whole of Ukraine and has tried several times to assasinate Zelensky, just like he has assasinated many others (and tried but failed to assassinate a previous Ukrainian president with poison).
The internal politics of Ukraine are just a pretext that Putin is using to realize his ambitions. They are not a reason in any way for the war crimes and attrocities he has committed.