Now multiply those cultural differences by 192 sovereign countries and it becomes easy to see why having one common culture becomes so important.
Now that I think about it; one of America’s (and many other country’s) biggest problems is we have two distinct but opposite cultures. Left and right ideologies which will never reconcile. In fact it’s just getting worse by the day thanks to the left. At some point the last straw will hit the horse with the horse bucking it off while spraying the fan with projectile diarrhea. Yep; gonna be messy.
In a perfect world all the leftists would live in their own (twisted) country while us normies would have the rest of the world.
China is not a uniform culture... There are actually over 72 distinct peoples, as I learned in a history museum in Shanghai, such as Yigurs, Tibetans, etc. The Han chinese enforce uniformity through brutality and “re-education”. We could follow suit in the US, but then we wouldn’t be the United States of American anymore.