I think that is the main idea. FO3 was similar, but not as stark.
Like the movie War Games, where "The only way to win is not to play;" the FONV endings are meant to illustrate the futility trying to affect the outcome when the aggregate of humanity is slave to human nature.
While "war never changes" is succinct as an aphorism, a less poetic but perhaps more explanatory presentation would be that Man's proclivity and predilection for war never changes.
This just cheered me up strangely ( but I am strange, who said that? ).
I've been trying for a week to think of a way to rationalise why you can only fix it for one faction only, rather than continue the stalemate.
You just presented one to chew apon :foodndrink: .
Though technically having a stalemate would be a never changing war... damn it ....