Although China has been invaded and subjugated a number of times only to rise from the ashes. Perhaps the better question isn't if the United States of America will fall like the Chinese dynasties of times long past, but whether America as a nation (like China (no PRC, ROC, or any particular regime in China)) will fall like the Roman Empire into different peoples that will merge as their own nations. What is boils down to is the question of whether the US is a union of several different cultures with very little unity or one culture with minor regional differences.