How long is it appropriate for a country to be "on top"?

[FEMA Camp Administrator]

This is probably a really dumb question, but as an American, I'm somewhat accustomed to the idea of the United States as some sort of world leader. The fact is, however, this is not normal, not even by the standards of the developed world, where most countries with maybe 2-3 exceptions were regional leaders at best. What I'm driving at is whether or not the United States being "in decline" (whether in terms of political, military, or economic power compared to other countries) is not only normal but totally acceptable from the perspective of national trajectory. We held substantial power from the end of World War II at least, and in many ways still hold much of that. I'd say that's a fairly good run compared to other nations.

[jaichind]

The short answer, based on my very amateurish and subjective reading historical evidence: around 200 years

Long answer: A couple of years ago I did some research to answer subjectively "what is the greatest empire ever"?  The way I did it is I would rank all powers from 1st to 10th every 20 years from 2700BC to 2020AD (every 50 years before 700BC).  Then I assigned points for coming in first, second, and so on (much like the Olympics 5 points for a gold medal, 3 points for the silver medal, and 1 point for a bronze medal).  I weighted each year by the LOG of the estimated world population (on the premise that being #1 in 2020 is much more impressive than being #1 in 2700BC) and then just added up the points for each political entity.

The greatest empire under my subjective method, btw, was Sassanid Persia. 

Separately I also defined "hegemon" as a power that is ranked 1st or 2nd for that time sample.  Once I ranked all the political entities by my metric I also looked at how many years each one of those powers was a "hegemon"  What I found is all of them could not be hegemons for more than 220 years. There were only 3 exceptions

1) Egypt 18th dynasty: "hegemon" for 250 years - mostly because Mesopotamia was in chaos during this period giving Egypt 18th dynasty a long run at being on top

2) Chinese Westen Chou dynasty: "hegemon" for 290 years - This is because Western Chou was hitting its peak during the period of Bronze Age Collapse in the Mediterranean giving it a free run at being on top for more than justified.

3) Sassanid Persia: "hegemon" for 360 years - This is for two reasons. First Sassanid Persian nobility was always at each other's throats which gave all of them an incentive to make sure the House of Sassan is around to balance out their rivals.  Second, Sassanid Persia hit its stride around the same time the Roman Empire and the Chinese Han dynasty went into decline giving Sassanid a free run at being on top for a very long time.

All other vast power in history can be "hegemon" for at most 220 years.

Based on this data one can expect the USA which started being a "hegemon" under my methodology in 1900 to drop out of the top 2 in the world by around 2100 or 2120 at the latest.

[The Mikado]

Based on this data one can expect the USA which started being a "hegemon" under my methodology in 1900 to drop out of the top 2 in the world by around 2100 or 2120 at the latest.

Calling the USA a "hegemon" anytime prior to 1918 is really suspect, and frankly, I'd say it's unwarranted until 1945. You could make a case for the USA as the single most powerful nation in the world in the interwar period but it'd be a hotly contested case and it certainly wasn't obvious.

The USA does take the position as the world's highest GDP country in the 1880s and has held it continuously since (PR China will likely take the title in the early 2030s, but a 150 year run is incredible), and the USA was undoubtedly the hegemon of the Western Hemisphere during the late 19th century to present (in really negative ways, especially, in the early 20th century), but the idea that the USA had greater international influence than the UK or more formidable military prowess than Germany in 1900 is pretty laughable.

[jaichind]

Based on this data one can expect the USA which started being a "hegemon" under my methodology in 1900 to drop out of the top 2 in the world by around 2100 or 2120 at the latest.

Calling the USA a "hegemon" anytime prior to 1918 is really suspect, and frankly, I'd say it's unwarranted until 1945. You could make a case for the USA as the single most powerful nation in the world in the interwar period but it'd be a hotly contested case and it certainly wasn't obvious.

The USA does take the position as the world's highest GDP country in the 1880s and has held it continuously since (PR China will likely take the title in the early 2030s, but a 150 year run is incredible), and the USA was undoubtedly the hegemon of the Western Hemisphere during the late 19th century to present (in really negative ways, especially, in the early 20th century), but the idea that the USA had greater international influence than the UK or more formidable military prowess than Germany in 1900 is pretty laughable.

Sure. This is a word definition calibration issue.  I merely defined "hegemon" as being in the top 2 powers in the world.  I am happy to use a different word as I agree top 2 is a bit of a stretch for that word.  My point is that from an amateurish and subjective statistical analysis one can say that the USA will fall out of the top 2 powers in the world by 2100 or 2120.

[Aurelius]

Don't see why it's inappropriate for a country to stay on top for a long time. The Romans were on top for centuries. Obviously, as technological change has accelerated and with a more interconnected world, these cycles have become shorter.

[PSOL]

Given our immense navy, I don’t see the decline happening until the US is unable to exert power projection any further from Hawaii or making it to engage in Europe. That won’t happen for a long time, and would require a costly naval war. I still think that we would still be top dogs in the America’s for even longer, as our neighbors have no ability to power project.

I really do believe that any sort of collapse in the United States would require domestic upheaval to weaken the United States. Unlike Great Britain we have a pretty stronger lock on our colonies and would require constant infighting to keep us distracted. The Romans were beaten by various ethnic and ideological conflicts pitting people against one another—plebians, Levantines and the ideas adopted across the empire, and Gallo-Germanics all tearing into each other and the establishment patrician class. We have rising swings of anger from the urban working class, small businessmen, Appalachians, migrant workers, Latinos, socialists, Nazis, and others all at each other’s necks and at the state.