That's great!
. . . but they're still living under communist slavery. So, it doesn't matter that they have a slightly unbroken chain of civilization, they don't have (never did have) a government that protects individual freedom -- and neither will we if our government continues down the path it's going.
My point was that the premise of the purported author is incorrect.
Most of the great civilizations of world history never had periods of anything vaguely resembling freedom or democracy. In fact, of all the ancient civilizations, there are only really two that did. Those were Greece (in its many city-states) and the Roman Republic. Since both were slave-based and quite restrictive on who was a citizen, even their “freedom” was largely illusory by modern standards.
That the supposed author thinks these two outliers make up a survey of world civilizations tells us little about world history, but much about his parochial vision.
Meanwhile, in the real world, civilizations that were never democratic or “free” plugged along for thousands of years.