Strangely, some national anthems (e.g. European ones) are taboo - the mark of supremacist colonialism etcetera, whereas others are encouraged - noble expressions of cultural identity that we should all join in with.

Here is the Algerian national anthem being sung during a demonstration at the end of my street in Paris.

It contains lines such as "we have taken the noise of gunpowder as our rhythm, and the sound of machine guns as our melody". The French sing "may a tainted blood drench our furrows"; and the British "scatter her enemies, and make them fall". Standard martial stuff; the idea being to puff chests and shout who's best. But imagine the liberal-thinking reaction to an ethnically homogeneous crowd of young white men waving the national flag in the Paris streets singing La Marseillaise, or in London chanting God Save The Queen...

The paradox of multiculturalism is that it shelters a load of ethnocentrisms, which are innately in opposition to it. (And the paradox of some ethnocentrisms is that they might not be able to even exist outside of a multicultural harbour.)