As an American, you should be relieved to have us, non-native English speakers to debate with: we make your English sound as good as the Queen's
Once one culture becomes so nationalistic that it intends to dominate and invade other countries, nationalism is a requirement for self preservation. Nationalism in the modern world is by large a byproduct of propaganda so that conventionally undesired ideas can become popularized within the public. This is also seen in outsourcing for instance. A first mover in extreme outsourcing forces their competition to outsource for self preservation. If the competition does not outsource, they will lose so much business and be taken over by the outsourcer due to their inability to compete on price. Basically, if there is no extreme nationalism which exists in the world, extreme nationalism is not required to exist.
Dont forget ignorantly as well.. Most Americans dont have a clue of what American culture is. Everyone is swayed back and fourth by a political system that makes you THINK you are politically exceptional. By accepting this proves that most americans are politically unexceptional.
"Nationalistic feelings are at their strongest and most violent when..." The culture of the nation is perceived to be under attack. German art was being radically transformed from this: To this: Jewish-inspired art of Weimar Germany:
Any nation that does not get it's carbon emissions under control, or ensure all citizens have equal rights is not even close to exceptional politically.
I glad you brought that up, in college (a thousand years ago) my professor would show us clips of debates and we were required to make the following decision after a politician was asked a question, did the politician: A. Answer the question B. Change the subject C. Wave the flag (make the subject somehow a matter of patriotism) Things haven't changed much in 40 years with the possible exception you could add "D" and say "make it a matter of christian morals" Pull out a piece of paper next debate, give it a shot.