What you are calling the shadow side of individuals I see as original sin. What you are calling the shadow side of religions and nations is another matter. Nations are simply geographical/political areas. They cannot have shadow sides, it is impossible. The rulers of the people in these geo-political areas certainly have shadow sides. The shadow side of Nazi Germany was the free reign of the sinful nature of it's rulers at that time, and the people who supported them. There were many Germans who didn't support them, many who did nothing out of fear or because it wasn't them personally being persecuted. Blanket blame over the entire nation of Germany is unjust.
A religious doctrine can have a shadow side. I don't know a lot of Muslim doctrine so I can't speak for that. Christianity as in living as Christ taught does not have a shadow side. The individuals who are Christians certainly do have shadow sides (sinful natures), but these are flaws of the Christians, not Christianity. The two are separate things.
My observation has been that the term fundamentalist is generally used to describe those Christians who place the rule of God over the rule of man. They do not accept that other men have the right or are fit to rule them. This is extremely threatening to those who believe men should rule each other, that people can be made good or should be controlled by the "right" people....state worshippers. That said, I do realize that a lot of professed Christians are really state worshippers, wanting to enforce their way of life and beliefs through the state rather than trust God to gather His flock. This drives would be Christians who realize this is wrong away from Christ, ironically. Why is it easier to believe that entire nations are collectives with a collective "shadowside" than to believe that man has a sinful nature?

"My observation has been that the term fundamentalist is generally used to describe those Christians who place the rule of God over the rule of man."



H. L. Mencken's definition: a terrible, pervasive fear that someone, somewhere, is having fun.

LOL. Yeah, Mencken wasn't a Christian, had no respect for the "booboisie" in general and religious "booboisie" in particular. But I really don't see the term "fundamentalist" used except in cases where a doctrine is espoused that threatens state sovereignty over men and asserts God's. This includes those misguided types who push for government to enforce their notions of what God wants, which may be right or wrong. For example, churches that lean leftward and "call" for government to bring "social justice" (economic redistribution and gatekeeping) are never called "fundamentalist". The Catholic Church is not considered "fundamentalist", it is no longer perceived as a threat to the state and many of the Church's priests are socialists, pretty much state worshippers and without faith in God. Ironically, I kind of think it's an appropriate term, What can be more fundamental than deciding what/whose laws to follow and realizing God's law is the base of all peace and justice?