I believe national identities are one of the most curious and interesting aspect of humans. I think people not only have a natural tendency to evolve in groups, since we are likely to be affected by our surroundings, but to form similar identities as well. Language is a good proof of it.
The ruling groups are sistematically trying to destroy this apect of humans, by overly exposing us to technology and even moderating the language we use... As a nationalist, I think besides race itself, people should seek to preserve the collective identity of your own family first, since we can in fact pass on some of the traits we learn to our children and the whole nation should engage in eugenics of this kind in order to protect the genetic legacy of the groups as a whole. Many people only focus on race itself, but I think that this is a matter of overall biological hygiene as well.
Since I believe people have a tendency to evolve in a Lamarckian fashion, I think that placing the group in a state of constant conflict should be the ideal way of taking care of eugenics as well. Not by fighting against other groups but probably just practicing martial arts.
there doesn't seem to be anything here