Now a days I think Russia’s interest in Ukraine (and Belarus + other ex Soviet states) is geopolitical more than anything. When you think about it Russia’s geography offers it natural protection on all sides except the West which leads into the rest of Europe. The marshes and fields of Ukraine/Belarus really offer Russia no protection against a European invader which is why Napolean and Hitler were able to go so deep into Russia before being stopped by the Winter. Ukraine and Belarus are buffer zones for Russia (much like the Warsaw pact was) to prepare for a European attack. Russia seems only interested in Crimea not only because it’s Russian population but the access to a warm water port. For decades (centuries even) Russia has sought access to warm water ports. Russia wants to assert political domination ( maybe not direct annexation unless totally necessary) over it’s Western neighbors mainly for self preservation. I’m not trying to make a pro-Russia post here since it’s no secret Putin can be quite brutal but I’m saying I understand the geopolitical reasons.