We've actually shot ourselves in the foot with a shotgun in the last few years. We're doing everything we can to cripple ourselves and let other powers take over.
These are not inevitable problems. Our politicians just don't understand the difference between land and capital and have undermined U.S. efforts to promote land reform in Asia after it worked so well in Japan.
The US and Europe squashed home grown communism mostly through things like social security, unemployment insurance, and a helping of good old propaganda. Yet, we where suckered into fighting ideology on foreign soil with military force.
I don’t think it was obvious at the time, but going forward we need to learn from these mistakes.
Korean War can be viewed North Korea as a separate country attacking South Korea, or a civil war. But, Vietnam war (including invasion of Cambodia) and a host of South American wars where much more clearly started as civil wars with Forein support not really invasions.
PS: Afghanistan is something of a wash with the US also invading the country.
Rome by comparison took 700 years to grow, and 200-plus to collapse
By comparison, when Rome fell apart (which admittedly took some time), the standard of living was objectively much worse for average Romans. They went from a civilization with plumbing, toilets, cities, aqueducts, a Coliseum with water shows, and probably the highest standard of living in the world, and a society with specialization of labor, education, rule of law and a well-developed legal system, to feudalism, where they lived under feudal lords as uneducated serfs living in huts and working in fields. It took over 1000 years for western society to get back to the level of technology and development they had under the Romans.
It would be better to treat the British Empire and the United States as two forms of the same empire, as they both speak the same language The capital of the empire simply moved from London to Washington via an internal revolution, a process that's happened many times in the past, e.g. Lisbon to Rio de Janeiro, St Petersburg to Moscow, Xian to Hangzhou, Kyoto to Tokyo. So the British Empire/United States reached a peak after 400 years, and is now declining for perhaps a few hundred.