> Do you stand up, put hand on heart and pledge allegiance to your family? Your church? Your friends?
I didn't pick the marriage ceremony my culture used. If it involved a hand over your heart I wouldn't have worried about it.
> Why would you do that for your country?
That specific gesture aside, perhaps because I cared about the ideals it represents and the words in the affirmation.
> It's nationalistic nonsense that has no place in a modern, democratic society.
No. Without some sort of bond to those around me why would I respect their views enough to allow a democracy? It's because we share some goals and ideals. If I thought you hated the things I loved about my country I might see you as an enemy, and vice versa, but if we see that we share our dreams we can survive not sharing any other opinions.