“This is not a matter for the USA to get involved in.”
It is certainly the matter for the US to get involved in.
Just not with troops. Russia is a national security threat (it amazes me that the isolationist fringe of the conservative movement repeatedly asks, “what is our national interest?”, or more ignorantly state, “we have no security interest”)
Russia is an historical enemy. It supports the Iranian and other rogue nations with ballistic missile technology and other inflammatory systems. More importantly, due to its recent weakness in geopolitical and economic interactions it has become more totalitarian, more oppressive and more aggressive toward its border states. ** Nations are moving away from Russia, not to align with the West or the EU, but to get protection from a desperate Russia.
There are a multitude of non military avenues to punish Russia for its illegal actions and annexation.
So, no, don't ask me to worry about Russia, a country that supports religion, stands up to homosexuals, has a flat tax, and an economy that's improving.
If the US would butt out, perhaps the EU would become more responsible for what's happening. The US is enabling Europe to not defend itself, while we're not defending our own homeland. If the US would get out of it, everyone would probably be better off if Germany, Poland, and Russia figured out what to do about Ukraine, which by all accounts has failed at nationhood.