This mentality is an product of the concept of total war, born of the French Revolution. Eric von Kuehnelt-Leddihn writes in [Leftism]
"[Limited professional- and mercenary-fought cabinet wars] came to an end with the French Revolution. And since all able-bodied men had to serve, whether they had a natural talent and enthusiasm for war or not, they and their families had to be propagandized and indoctrinated. Now nation was pitted against nation, not merely government against government. This new concept of total war was the natural result of the two totalitarian trends toward democracy and toward identitarian nationalism." [391]
This is one aspect of human behaviour. Left vs Right, French vs English, Christian vs Muslim, Catholic vs Protestant, White Army vs Red Army, White vs Black, Rich vs Poor, my town vs your town ... the list is endless. It's called "Othering".
Humans are predisposed to adopting that kind of thinking.
Right, and Leddihn would go on to talk about the ages-old pogroms in Poland and ancient tribalist energies. That said: prior to conscription, nationalism, and codified identitarianism, in the West, wars were rarely conceived of or carried to last man standing. In Europe, this had much to do with the intermarriage of the monarchs, among other pre-modern characteristics detailed in 'Liberty or Equality'.
OK. Seems like angels dancing on the head of a pin to me. I haven't personally run into anyone "conflat[ing] a people (e.g. Russians) with their tenuously-linked government (Putin's regime)"