I lived in USSR, and know first hand that it means to be separated from common technological space. USSR wasn't that small, especially if one adds Eastern Block, yet it was falling behind the world becoming fully incapable to produce their own comparable computers, cars, etc.. If world get to split into such islands, the speed of technological progress will fall dramatically while social progress may go fully backwards. If you look at some ideologies rising around the world - they are straight medieval, and in many cases only connectedness to outside world has been preventing them from taking over their "islands".
Adding USSR into the discussion greatly increases complexity of the discussion. From analysis I've read, central planning is supposedly fine when country doesn't have much industry, because to start things up, it can provide essential investments and starts organizing production. But when country is somewhat developed, efficiency starts to matter and top-down approach to decision making of central planning vs bottom-up decision making mechanisms of markets produce different results. Politics and other things are important factors too, but I think that would be too much for this discussion.
As in -- "no technology to speak of" is a gross misrepresentation of the reality of the middle ages. The fact of the matter is, they were strictly more technologically advanced than the classical Romans, with inventions like the heavy plow and three-field rotation improving agricultural productivity significantly beyond what Romans had achieved.
> The fact of the matter is, they were strictly more technologically advanced than the classical Romans
No, they were more advanced in certain ways, but the original contention is correct that they were less advanced in others. Notably they were unable to build domes. They were also less productive, so less advanced in an overall sense.
Charlemagne empire wasn't an interconnected fabric of roads, trade, centralized administration and so forth, ie. it wasn't all that that Roman Empire was, and all that having gone is the fall of Roman Empire. Charlemagne empire was just an aggregation of conquered lands under his personal rule which thus he easily divided between his sons.
Yes, but my point was that a large state was created and managed centrally for quite a long time, and even the successor states were large.
More than that, technology continued to evolve. The Romans had nothing like Medieval plate armor, for example. There are many examples of better tech from the supposed "Dark Ages".
