Yeah, it was really just a quick look on the train. My train journey is about 30 munutes, I probably spent about 20 minutes skimming over the link and reading anything that looked a bit interesting in a bit more depth.
The stats he provides look pretty compelling but.... he's cherrypicked those a bit, hasn't he? The Soviet Empire lasted a lot less than 250 years. As did the 3rd Reich. As did the Japanese empire.
A couple of things he said made it clear that he wrote it before the single European currency came into effect, and before travel within the EU became effectively passport-free once you are in.
It was obviously also written before globalisation came into effect and barriers to trade were largely eliminated. He spoke about how in the ancient empires people could purchase goods from far flung places and compared that to the restrictions on trade in place in 1976. Well, if I go to a shopping mall here in Australia I would be very hard pressed to find anything at all that isn't from some far-flung part of the world. About the only products that are more local than imported are perishable food items.
In terms of the end days of an empire (or superpower that often behaves like an empire), well I'd say it's fairly obvious that the United States is in decline as a global power. Globalisation IMO has a lot to do with that, shifting so much manufacturing and services offshore in a corporate "race to the bottom". It's not really a great path to prosperity unless you are a billionaire.
He also spoke about the great cities of empires becoming racially diverse. In modern times, it seems to me, this is more about globalisation and neoliberalism. The city I live in has never been the capital of an empire or anything remotely close to that, and yet the racial and cultural diversity here is off the charts. It's the same in many cities around the world, except maybe in Japan. And being more racially and culturally homogenous certainly hasn't prevented Japan's decline as an economic superpower.