As I've written in my article on nationalism in Convivial Hermit #9, nationalism is a kind of modern tribalism with ingrained outsider/insider biases that are to some degree hard-coded in the human brain.  I don't think anyone can be entirely immune to this group bias as it is manifested today but still one can certainly analyze it and pick it apart as much as we can analyze why we need to eat while still eating.  To me it has always been strange as it was never instilled in me that I need to care more for one group, or indeed one person, than another, especially as in my life I've been saddled between two cultures, not having been born in the country in which I live.  I think that's given me a different perspective that people of one cultural identity lack.  I can to some degree more readily observe this behavior from the outside and note down the way it makes people irrational, separating whole millions of individuals of diverse viewpoints and mentalities into homogeneous units or blocks.  This is the power of symbols.  But what's more, this occurs in the objective realm in which the topic at hand is completely subjective, nations being social constructs that exist only in the brain.  This bond between irrelevant things causes people to go so far as to murder strangers on mass scales, or consider the death of a stranger under one tribal symbol as superior to another.  Benedict Anderson wrote about this famously in Imagined Communities: Reflections on the Origin and Spread of Nationalism.  The subject is not as simple as I make of it but it still never ceases to repulse me in the acts of utter stupidity that it inspires, and particularly in the hypocrisy of nationalists who claim morality while equating those waving one symbol as greater in value than another, having no objective basis for any of their beliefs.  Nationalism is the annulment of objectivity and the celebration of sheepishness and group-think on a massive scale.  This is apart from patriotism, mind you, and has no bearing on the culture and art and music and tradition resultant of nationalism, which requires separate reasoning.