In my opinion, the only reason why there is some kind of peace on Earth right now.. is that many countries have atomic bombs. If you do some serious sh!t, you have to fear that someone else drops the bombs on you.
Eh, I don't think so. The atomic bomb is a weapon that's outdated because most modern warfare is guerilla warfare, and an atomic bomb is overkill that would create far more problems for a wielder than it would solve. There are plenty of states who have atomic weapons who are in ideological conflict with states who do not, and so do not need to fear retaliation, but they still know they sure can't use them because of political pressures (ex: Israel and Iran). Plus, the world is interdependent enough that
any war within a developed country's borders would be highly disruptive and disastrous for everybody. Nuclear deterrence is outdated, and I highly doubt anyone in the modern world is thinking "Well, we'll have to use these again at some point to maintain this "peace." That part is an explicit feature of Nagato's philosophy.
Nagato in the modern world would be viewed as a paranoid hyperconservative, not really a scion of peace. His philosophy, like most of the antagonists' in Naruto, springs from trauma and spite rather than rationality and an actual desire for peace.
Really, if you go with this "The characters represent wartime and peace-bringing ideologies," then Danzo and Itachi are more emblematic of modern practices of the American/British military and intelligence community (being secretive, committing horrid acts and treating civilians as collateral damage, claiming it's in the name of peace). Itachi's the equivalent of a traumatized field operative; Danzo is command. Ultimately, all Danzo does is fuel war (creating people like Sasuke, who is basically a guerilla fighter in this mindset, seeking to destroy the establishment because of how he perceives it has wronged him - he's like, ISIS minus the religiosity). Itachi can be seen as honorable and self-sacrificing, but his ideology was too ineffectual against Danzo's, and failed to prevent a lot of damage (so, he's a soldier, basically).
If you think of Sasuke as a guerilla fighter, then Obito is basically one too. Madara Uchiha is more like the despot/autocrat/commander of the guerilla forces, manipulating the trauma of people damaged by the establishment for his own insane gains.
Hagoromo's an ineffectual hippie. Naruto's some idyllic example of military force that can resist the guerillas fused with empathy and compassion that somehow manages to turn the guerillas to the side of cooperating with the establishment.
...Meh.
