That would be an invasion of OUR country. Quite different from a border war between two nations that we have no interest in, nor any commitment with
The fact that you cannot justify our involvement in this and try to equate it to an invasion of us or NATO demonstrates the weakness of your position.
I have no problem justifying US security interests in Europe.
Kicking Russian corruption and influence out of Europe is certainly in American interest. Economically, politically and morally. President Trump agrees and his policies reflect that. Economically because exporting energy to Europe will create good jobs in the US. Politically because Russian corruption buys Anti US political support in Europe. Morally because no people should live under the tyrannical Kremlin boot. You don’t agree. That’s ok.