There are Russian nationals that live in almost all the countries all around the world. So that's not bonkers, the logic is sound.
Now what's important is when some region has mere fractures of a percent vs when its something like 25%. If your country has 25% Russians and you oppress them - I think Russia has obligation to defend them.
That's exactly what it is and I have no idea what sort of insane, convoluted logic you use to come up with any other idea.
but then it turns out that its arms can be used OUTSIDE of that block
Ohhhh, I see. You believe that defending from an invading force means that you can't attack anything beyond the border? So Russia could just build an ammunition factory right across the border and Ukraine is somehow morally bound not to attack it? Completely insane.