Libertarian stand-up comic Doug Stanhope has said:

"Nationalism does nothing but teach you to hate people you never met, and to take pride in accomplishments you had no part in."

I would only quibble with the "nothing but" part. The collectivist herd-think that is nationalism also teaches you to take offense at imagined insults that have absolutely nothing to do with you personally.

Take for example the outrage of American nationalists over President Obama's dealings with Iran. They denounce the nuclear deal that his administration negotiated (which on Saturday led to the lifting of international sanctions on Iran) as a total capitulation that makes all of America look weak.

Never mind that the entire Iran nuclear scare is, as Gareth Porter has thoroughly demonstrated, a phony, manufactured crisis in the first place. Never mind that the peace deal actually makes individual Americans more secure by decreasing the likelihood that their sons and savings will be sucked into yet another disastrous war in the Middle East.