Every Witcher has a different perspective, and they wach think uniquely like humans.
Geralt thinks politics are ways in which the rich and privileged plough each other and the common folk to get richer and more powerful, and he believes that wars are a mean for the same rich assholes to sacrifice the lives of idiots who call themselves patriots or those who are force to fight in order to either get richer and more powerful or preserve their status. As a result he does not care about politics, wars, North, South or any other affiliations, and he wants to be left alone to live his life in peace.
On the other hand we have Coën who fought and died in the battle of Brenna for no apparent reason. Maybe he was fighting a war because he had a patriotic side to him, but who knows.