I won't speculate exactly how world affairs are going to shape up over the next few decades. I'm looking at it purely from a complex system's perspective.
I agree that the established super-powers are being torn apart by concomitant internal and external forces acting to disintegrate the current system paradigm. However ultimately, these forces are the result of what economists call "transaction cost" (internal and external, the cost of any sort of transaction inside or outside a firm. Be that money, resources, information, or commands). The better power can enforced (the lower the internal transaction cost), the larger an economic organisation will get. This is why it's no coincidence that the Industrial Revolution both spurred larger States (with Nation States) and larger companies (with Gilded Age conglomerates everywhere). Because if companies can get larger in their internal processes, States can also get larger in their internal processes. States exist in anarchy alongside each other competing in their enforcement of power, so once internal transaction cost is lowered due to whatever factors, States that do not step up will get "outcompeteted", meaning invaded/left to decline.
The Industrial Revolution (and really, the Gunpowder Revolution, the collapse of the Catholic Church, and the rise of trade) led to lower [INTERNAL] transaction cost in firms. Production lines could be set up and thousands of workers could be commanded. The same way, armies could be set up that benefited from the beneficial scaling of gunpowder in combat. But since the 1990s, a different process has started playing out, the [EXTERNAL] transaction cost is falling rapidly (thus also the cost of warfare and by extension "terrorism"). Due to the internet, new manufacture technologies, and advances in technology in general, the economic cost of outsourcing has been in a free fall. This of course has effects on the State, but they are still slow to move. Communism was the first to go, which was the epitome of internal firm process orientation. The USSR collapsed in 1991 under its own weight (arguably very much the same way the EU is colapsing), the Eastern Bloc fell apart, China opened up their economy, so did Laos and Vietnam. All the proxy revolutions that the communists have been funding suddenly run out of steam or converted into something else (cultral Marxism). No matter how weird it seems, overt communism died in the 20th century but its spawn took root in the west and infected all of it, which is leading to the West's colapse. Thus I argue that the vacum that was created by the overt collapse of the Soviet block is actually tearing the West apart.
Next comes the ongoing collapse of the Nation-State. For this it's important to understand what lower external transaction costs for States mean. As States are territorial monopolies, lower external transaction costs will mean the following
1. higher rates of outsourcing their services, the State will be more likely to primarily deal with actual governance than to micro-manage a dozen services. This can occur explicitly (the lack of explicit institution for new economic sectors, regulation instead of a mandated monopoly) or in more subtle ways (the rise of people "opting out" of government services, school choice is an obvious example, but we can see the same occurring for even security).
2. lower territorial control. Another way of State size to decrease is for its territory of monopoly to decrease. We can see this happening for example with the digital nomad phenomena, increased tax evasion, and the most important part: secession. If there has been one tendency for 21st century conflict, it has been guerilla warfare and secession (take Ukraine and strife in the Russian Federation and even the US as examples). With firearms themselves becoming something a ***** can manufacture in their bedroom and $100 drones being viable on the battlefield, we see the continuation of the trend that started in the late 20th century. Due to purely economic factors, it is becoming easier to evade and oppose power than to exert it. This is similar to what Zbigniew Brzezinski (handler of Obamabongo) stated in 2008 “In early times, it was easier to control a million people, literally it was easier to control a million people than physically to kill a million people, today it is infinitely easier to kill a million people than to control a million people. It is easier to kill than to control.”
So yes, technology is pivotal and always has been. How power can be exerted depends on technological factors. Taxation is not worth anything if a peasant is hundreds of miles away, nor is it worth anything if the subject keeps it in cryptocurrency and can fly to another country for 20 euros the next day. While in the past other factors contributed to the "cost of violence" more than technological advances (terrain, famines, transportation costs), technology itself has circumvented them by now. We will see a return to a more Medieval setting, with smaller mini-states. But we'll also see a lot more inter-state activity than in the Middle Ages. It's not a future everyone will like (hence the ever growing neo-Luddite sentiments mostly by the people dependent on the Welfare State), but it's something that everyone will have to face, especially with the rise of AI. Or maybe there will be hideouts, little Welfare-States like North Korea is today. Ultimately though, they will have to enforce strict immigration requirements.
And on a latter note, large Nation-States did not exist in the Medieval Ages the same way they do today. Most peasants didn't even know about their king, so even if there was a larger "Nation" like Russia or France, it was just a unity of nobles. This was quickly phased out after the Gunpowder Revolution allowed the kings to take actual power (rather than a complex, multilayered system of barter that was the Medieval ages) in the Modern period, yet most people still confuse that with the Medieval ages.
In conclusion I think that spread-out decentralisation will be the way forward for the next stage of history.