First of all let's talk about an objective way of regarding your country. This can't be done easily by everybody, it is hard to achieve the knowledge about true history and true politics. For example, a Romanian may find it hard that his country is and was irrelevant on European scale or that Hungary has bettered Romania in most of the clashes. Same can be said about a lot of nations, such as Poland or Slovakia, to name some. Reality is a harsh thing.
Therefore, nationalism is something for the weaklings who cannot accept the truth. Nationalism hasn't led to anything, and, furthermore, is pointless.
A feeling of supremacy can and should exist, but again, it is hard for an Albanian, to give an example, to heed the fact that he is superior to some nations and peoples, but inferior to some others.
Nationalism is also embraced by the sheep because they don't have anything to refer to, they have no remarkable qualities, so they resort to nationalism in an attempt to be proud of something. They don't mind being part of the rabble and obeying everyone without asking (therefore, they do the same once they reach power or within their families), as long as this makes them able to be even more proud of their country.
Because of their gregarious mentality, most of nationalists are devout Christians, a religion which allows and, even more, enables the herd mentality. A normal people seeks to destroy what is sick, whilst Christianity seeks to enable the sickness even more, through means such as "love for every human" and despising selfish nature of the man.
Thoughts?