I see nationalism, as a kind of mentality that presumes other nations or ethnicities as inferior, no matter where it springs from, as dangerous and useless. Whatever the source and origin of any nationalism, it is only based on subjective inaccurate thinking and lack of open-mindedness.
Let's think about Iranian nationalism which would be the closest to our Iranian understanding and background. I do not agree to even think that we Iranians would be superior to any other nationality, whether Afghan, Arab or African.
Nevertheless just thinking about any sort of supremacy is quite different from expressing it. Expressing it is much worse.
I have very often sensed that many Iranians think they are much 'better' than their neighbours in the Middle East. The main reason they come up with is the fact that Persia or Iran is a very old civilisation and that there have been so many great Iranians or Persians that have contributed to the civilisation of the world.
I, as an Iranian, have a few arguments that should go against any such thought of superiority.
First of all why shouldn't we think that Mesopotamia is a much older civilisation but there is almost nothing left of neither the Sumerian, nor the Assyrians or Babylon!
I know that Greek civilisation, without the military side of it, has had enormous contributions to science and civilisation and they regarded the then-Persians, especially Xerxes, as arrogant and uncivilised.
Although I am quite aware that there are a lot to be proud about but it's very important to know that there are also many others, other peoples, that are no less and there have always been, even much before us.
I am sure that the great scientists and philosophers of Iran were very open-minded men without any prejudice towards others considering themselves as mere human beings. That is what makes a person really superior; to know that he is just a humble human being and nothing more.