This is the set of tropes that cluster around Knight Templar: the forces of light in hardcore mode, excessively or otherwise. This mentality is all the way over on the Idealistic side of the Sliding Scale of Idealism Versus Cynicism -- but it has nothing in common with modern idealism of the Granola Girl and Cloudcuckoolander variety. Of course, that doesn't mean that non-European heroes can't act like this -- and it doesn't mean that European heroes always do, either. The Roman-derived tradition of "My Country, Right or Wrong" was always present in Europe...