[teebs]

I think the difference between now and ancient Rome is that we're used to a higher standard of living, and technology and information are more accessible to all. I think by "unsustainable" he means that we would be likely to have a violent revolution. This is not unrealistic. Revolutions have happened because of inequality before. I'm no history expert, but I think you could argue that both the French and American revolutions were related to inequality of power and wealth.

[judk]

The American revolution was upper class vs upper upper class, quite different from the French or Russian revolutions.

The USA didn't change much due to the revolution. The US Civil War was a much greater inequality-related upheaval