Direct comparative criteria for national collapse of the old world empires and modern societies are not exactly on the mark without some enumeration of points. They have fundamentally different elements and paradigms for nations. Roman civilization in its day was far ahead of most of the rest of pagan, ignorant Europeans. Celts had only relinquished their cannibalistic warrior ways in Switzerland with the appearance of Germanic enemies who marginalized them. Germans had stick villages. England had Stonehenge, yet it was probably short, darker people from Malta that migrated north to bring their technology to the cold isle. I wonder if the structure around St. Peter’s square could be said to imitate Stonehenge structure a little?
Italians are a Germanic people too, and the Roman Empire following the Etruscan inherited the knowledge of the very ancient civilizations to the south. Roman expansion through France and Britain was nearly like an advanced extra-terrestrial civilization arriving on Earth where live the conceited hillbillies believe they know it all. Ancient Roman Civilization took the best of the near East and Greek knowledge too, and brought everything to the far west and north.
Roman civilization was due to collapse when it had served its purpose of bringing civilization and Christianity to all of Europe. Christianity was the common tie that drew formerly pagan and violent peoples into a proto-modern-European Civilization. It became a violent Europe with rapidly developing technology tempered with Christianity in a largely illiterate social environment. Imperial Rome could only go so far and last so long. Tamarlane would surge into invading unto Iraq. There was too much going on up North and West, while Constantine moved the main focus of his ruling era toward the East in Constantinople where the Eastern version of the Roman Empire survived another thousand years beyond the west.
The United States compared to Rome has not yet fulfilled its destiny as a leading technological and cultural accelerator of human prospects within a democratic political economy. It is possible that branches of the United States may survive off-world longer than the terrestrial version- maybe ten or twenty thousand years. I would think if that occurred it would not be recognizably American except in name only should some uncreative group of people full of nostalgia for this millennium wish to call themselves the USA or America.
The United States hasn’t a history of owning foreign colonies- it is a trading empire with much direct investment in foreign entities. It hasn’t foreign possessions to lose. True it was stuck with the Philippines for a few decades, yet it rectified that when practical to do so.
It is possible that the rapid decline in Christianity in the United States could precipitate national economic and social collapse. Rich corporations tend to be over-promoting their existing values and methods to the detriment of democracy’s marketplace of ideas. Good ideas may have few readers as the authors are marginalized in the commercial ecosystem.
Perhaps Mexican illegal aliens and other Latinos will bump out the existing cultural composition in the United States and transform the nation into something else- a Nova Mexico, through evolution and leadership weakness in the U.S.A. Alternatively China may absorb America like the Borg absorbs civilizations as Americans hand them the political economy on a silver platter because of cheap labor and sales opportunities in China. No one ever said the Chinese are stupid- they won’t look a gift horse in the mouth, as the saying goes.
The United States could fade away as environmental crisis overtakes the vanities of mass consumerism political economics. Certainly there is no political leadership aware of the science of ecological economics in the United States.
Alaska’s northern towns have warmed up a lot since 1976. The Alaska Climate Research Center publishes a chart comparing temperatures from 1976 to 2018, and the results are consistent with global warming observations and theories. The temperature change for Barrow in autumn, for example, is 18.0 degrees Fahrenheit.
Chart from Alaska Climate Research Center-affiliated with U.A.F. Geophysical Institute.