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...
If they considered it illegitimate, why did they sign a treaty guaranteeing Ukraine's sovereignty and territorial integrity?
The answer is because at the time Ukraine was controlled by Russian stooges, and as long as Russia had control of Ukrainian politics it was all fine. What they couldn't stand is the idea of a genuinely free democratic Ukraine sat right next to an oppressive and kleptocratic Russia. The Russian regime sees all of Ukraine as their back yard, every last square inch of it. They have even said so many, many times. Putin wrote an essay about how Ukrainian sovereignty is "only possible in partnership with Russia", and if you think he means anything like an equal partnership I can't help you. Crimea and the Donbas are excuses, they're a foot in the door to Ukraine as a whole.