The average age of the world’s greatest civilizations from the beginning of history, has been about 200 years.’ ‘During those 200 years, those nations always progressed through the following sequence: 1. from bondage to spiritual faith; 2. from spiritual faith to great courage; 3. from courage to liberty; 4. from liberty to abundance; 5. from abundance to complacency; 6. from complacency to apathy; 7. from apathy to dependence; 8. from dependence back into bondage.
the usa has aspects of a global empire. the empires were destroyed in the world wars. the usa has aspects of a nation state. but without common language and culture a nation state eventually becomes yugoslavia or the soviet union. the violent break up of the usa is inevitable, and if our nuclear weapons can be controlled or neutralized, i think this will generally be good for the planet. ,
When it comes down, and it will, the military will be THE deciding factor in what the new order looks like, historically it always has been.
This is quite broad and imprecise; the Ottomans and the Romans both lasted 600 years or so, and the Hellenistic period lasted almost 400 years. But I'll play along and put America around 5th or 6th place. Predicting is hard but I think there is a decent chance (more than 50%) that we will be comparable to say Serbia (Italy??) in another 50 or so years. Our movement through 5 to 7 has accelerated significantly in just the past 2 or 3 decades. Our problem (so to speak) is that we will be unlikely to just disintegrate into pieces but more likely to be taken over whole by some other empire like Russia or China.
At this point, we tend to blur the Roman Republic and Empire together, but the Empire lasted 500 years after they lost their Republic, so I imagine it could be the same for the US. Some version of the "United States" could go on, but it won't be anything we would recognize or admire.