It only gets to be a problem if groups of peoples that you are a part of happen to be directly fighting, which is not that common these days.
If that happens, generally speaking, give it a bit of time and once the Global Elites, the bankers, the politicians and the Arms Dealers have all had their fun and the money runs out, or one side gets the stuffing beaten out of them and has to fold, chances are things will go back to being at peace and the propaganda will flip from drumming up hatred to saying that it's wrong to be hating others because of their national origin. (Exactly the history of wars and peace in our good old USA).
So in the mean time you'd have to pick to either stay out of it (which may or may not be possible), or fight for the side you believe is right, to help liberate the other group from their evil & oppressive leaders.
Wars are for the most part about rulers and elites fighting other rulers and elites and the common folk are the ones who get ground into the dirt and die for the vanity and profit of the rulers and elites.