@flowingblades​

I mean, I agree, but also “immune systems” are bad wrt nationalism. A country is not an organism. A body needs to keep the body safe; a culture does not need to keep itself safe, rather it needs to keep the people in it safe.

The culture doesn’t need to be preserved if “culture” is just hot dogs vs sushi, ballet vs rap, basketball vs rugby.  In other words, if it’s just aesthetics.  Falling below a certain level of Nationalism makes it infeasible to field an army - but fielding an army to defend sushi would indeed be overkill.  However…

1. Consider FGM.  We now have it in Michigan, apparently.  For now, it’s still considered a criminal activity.  But what happens when 5% of the population supports it?  10%?  15%?  Eventually, it becomes more normalized and the political will to legalize it will materialize and be captured by some political party.  FGM is actively harmful and unironically bad.
   
2. However, that still only affects one group.  What about long runs of repeated first cousin marriage?  That’s a cultural thing, and the effects stack the longer it goes on, putting a disproportionate burden on the healthcare system.
3. But even then, you could hypothetically force the entire medical system to be ‘free market’ to make individuals pay for the burden of that instead.  So let’s step it up again.  What about who deserves the fruit of the economy?  Is the society individualist or collectivist?  Should we help each other or is it smart to screw each other over at the earliest opportunity?  Differences on this matter impact the political will to perform redistribution - either with no redistribution, some redistribution, or proceeding to Venezuela-tier “bordering on a failed state” botched Socialism.  That has a HUGE effect.  
4. What religion should be the dominant one, and should it have control over what to do with heretics and “degenerates”?  You know, like LGBT people are considered in some countries and territories, like, say, Chechnya.

Ultimately, culture is not actually individual and not actually escapable at the national level.  To keep the people safe, it is actually necessary to keep the culture some level of safe, particularly if that culture involves not becoming Venezuela or Saudi Arabia.