I a good question to ask have we stoped advancing as society which means the present prosperity is frozen

Also is the West and other places around the world decaying due to the lack outside frets which is one of many reasons for the decline and fall of the Roman Empire

The USA will not fall to an external enemy but to an internal enemy and being self-destructive which has an happened since the 1860s

I would say it's still very unlikely but I would say you may have a much better view of the USA