Since the subject of nationalism is so hot and heavy around here, I thought I would present some quotes on the subject that also express my mind:
Heroism on command, senseless violence, and all the loathsome nonsense that goes by the name of patriotism - how passionately I hate them! ~Albert Einstein
Patriotism is the willingness to kill and be killed for trivial reasons. ~Bertrand Russell
Patriotism is often an arbitrary veneration of real estate above principles. ~George Jean Nathan
Patriotism is your conviction that this country is superior to all other countries because you were born in it. ~George Bernard Shaw
A nation is a society united by a delusion about its ancestry and by common hatred of its neighbours. ~William R. Inge
Each man must for himself alone decide what is right and what is wrong, which course is patriotic and which isn't. You cannot shirk this and be a man. To decide against your conviction is to be an unqualified and excusable traitor, both to yourself and to your country, let me label you as they may. ~Mark Twain
The love of one's country is a splendid thing. But why should love stop at the border? ~Pablo Casals
Nationalism is an infantile disease. It is the measles of mankind. ~Albert Einstein
I have no sense of nationalism, only a cosmic consciousness of belonging to the human family. ~Rosika Schwimmer
To me, it seems a dreadful indignity to have a soul controlled by geography. ~George Santayana
You'll never have a quiet world till you knock the patriotism out of the human race. ~George Bernard Shaw
It is not easy to see how the more extreme forms of nationalism can long survive when men have seen the Earth in its true perspective as a single small globe against the stars. ~Arthur C. Clarke
I am not an Athenian or a Greek, I am a citizen of the world. ~Socrates
I couldn't help but say to [Mr. Gorbachev], just think how easy his task and mine might be in these meetings that we held if suddenly there was a threat to this world from another planet. [We'd] find out once and for all that we really are all human beings here on this earth together. ~Ronald Reagan, 1985
Nationalism is a silly cock crowing on his own dunghill. ~Richard Aldington
Patriotism is a kind of religion; it is the egg from which wars are hatched. ~Guy de Maupassant
Can anything be stupider than that a man has the right to kill me because he lives on the other side of a river and his ruler has a quarrel with mine, though I have not quarrelled with him? ~Blaise Pascal, quoted by Tolstoy in Bethink Yourselves
It is not for him to pride himself who loveth his own country, but rather for him who loveth the whole world. The earth is but one country and mankind its citizens. ~Baha'u'llah