Russia is literally surrounded by NATO in Kaliningrad and I’ve only seen it mentioned once somewhere on Twitter, and not by Russians. This is Russian propaganda to make westerners feel guilty and blame their politicians.
Saying "look at the map, NATO surrounds Russia" is sort of akin to looking at a map of city lights on the earth and calling it a heat map of murders. Not the greatest analogy, but hopefully gets the point across.
The crucial difference, in case is not clear, is that a missile placed in Ukraine would hit Moscow, the capital of Russia, in minutes. This is much more threatening to core Russia interests and Putin would not live with it.
Before rushing to putting all the blame on Russia just because "Putin-bad": I would strongly encourage people who are interested to know more to watch the following talks, from ages ago, given at reputable US universities because let's be honest, none of us is geopolitical historian two weeks ago on this topic so why don't we all do a bit more research.
[1] A good overview of the history, 7 years ago from a talk @ U Chicago. (https://www.youtube.com/watch?v=JrMiSQAGOS4)
[2] Another one from a talk @ Yale: https://www.youtube.com/watch?v=8X7Ng75e5gQ
In Crimea and in some parts of Donbas the inhabitants identify as Russian.
So what? So could one from Latvia or Estonia. (Not to mention Leningrad.) So you're saying that justifies him invading and subjugating those countries too, aren't you?