I don’t think that Im rationalizing, more like the opposite and saying that most people are similarly irrational, there’s no evil-gene that just they have.
That said, if they take up arms and go to kill innocent people then they obvilusly need to be put down. Similarly to how a dog trained by a dog fighter might need to be put down even if it’s just a pawn in someone elses twisted game. So yes these russians have to be killed in self defence until they leave.
All I’m saying is that i always find it a bit rich that people act as if they would always do the right thing in similar circumstance.