The United States has not spent $ 300 million a day on war in Afghanistan.

[Spongebob]

I don't see freedom as something that can be retained without the willingness to die for it, and I see very little will for that in any nation.  Democracy is not a default condition - it requires a balance between a strong educated populace, and a government strong enough to keep order.  If either side gets too powerful, we get populist autocratic revolution or an elitist oligarchy.

This is certainly true in the case of emergent democracies.  If you examine the case of the USA, we've had only three such challenges that truly required our people to die for democracy, the Revolutionary war, the Civil War and WW2, each nearly a century apart.  We chose to fight all other wars/conflicts.  I agree that democracy does not just happen, but it requires far more principled participation than anything else.  When leaders emerge who demonize large swaths of the population just for disagreeing, like Joe McCarthy and Trump, the truest danger to democracy becomes evident.  Our freedom is our worst enemy.  Because there is no one to swat down discontent, it has a tendency to spread like cancer if the circumstances are just right and there's no one to cut it out.  Unless something changes, I believe this will consume our very democracy in the near future.  Just consider the GOP's current behavior, destroying democracy in the name of saving democracy.

I see myths as central to the existence of a nation.  The myth of "divine right" held together kingdoms.  The myth of divine succession holds together theocracies.  The myth of "inherent rights given by a creator" holds together liberal democracies.

This has certainly been the case in the past, but I don't believe it is technically necessary.  No one has tried it so we really don't know.  The primary tenets upon which the USA was built are not inherently divine or religious.  If you remove just a couple of words from the DOI, it's basically a humanist manifesto.

Today, most people don't give a damn about liberal democracy, as long as they can buy the next iPhone.

On this you are absolutely right.  Selfishness (and rampant consumerism is but one aspect) is rotting the soul of our country.