Borders are imaginary lines that allow people to group together with a commonality. They can be both good and bad, just like individuals. Taking pride in yourself does not mean you need to belittle others, nations are no different. You can do well for yourself and lift others up at the same time.

There are two ways to have the tallest building in town...

Irish nationalism has been anti imperialist and left wing. It is not anti-migrant or supremicist. During the euphemistically named troubles, some nationalists up North took a strong and valid grievance against an apartheid state way too far. There were bombs that killed civilians including children. The unionist population could be considered British nationalists. Many supported an apartheid state. The British government, in addition to commiting war crimes directly (google Bloody Sunday) colluded with vicious unionist paramilitaries.I guess my point is that all nationalisms are not the same. High minded opposition to us and them mentalities is more difficult if you are one of the opressed in category "them'" I say this as a reluctant nationalist who likes the principle of there being no us and them and who harbours no hatred for any nationality.

Nationalism, like religion and two sides of the same coin, is basically an us vs. them mentality.

Moderate nationalism (pride in being a citizen of a country and in the principles undergirding the country is a plus. But, extreme nationalism -- ethnocentrism, racism, denigration of other, seeking dominance over others or exploiting them, and expansionism at the expense of others countries -- is destructive and repulsive. Trump's "America first" (placing international relations in a win lose" context) is an obnoxious form of aggressive nationalism.

The wave of nationalism sweeping the UK is dragging us out of Europe for entirely the wrong reasons. I don't have a definite side to take on all that, neither do most people here, the real benefits or problems with it don't get a mention in the press for those of us who aren't practised economists. All I hear about is immigration, which is a non issue. Just like the US we're sliding backwards at the moment.

Nationalism is sticking your tongue out at your neighbours and shouting "we're better than you!".

I agree with Einstein. Nationalism is an infantile disease.

Short answer? It's both.

Nationalism is the fervor of the fanatic

Gets the racists to vote

I have no use for nationalism or patriotism.