Can I make a match? I mean between major disruption and economic decline.
My hero, Matt Ridley, author of The Rational Optimist, writes about the natives who lived in Tasmania.
These were the same natives who arrived in Australia as paleolithic hunters 50,000 years ago. At the time there appears to have been a land connection between Australia and Tasmania. Some hunters went to Tasmania.
The connection to Australia was cut off about 10,000 years ago. From that point on the Tasmanian natives lost nearly all the paleolithic arts, from flint spears, a 21 herb pharmacopeia, the art of making fishing hooks and nets... they lost everything.
Ridley explains it in terms of lost specialization from diminishing population. Specialization (even passed from father to son) is the source of civilizational knowledge.
I accept that a society can regress when it shrinks or when its specialization is disrupted, as Tasmania experienced.
My question is whether: the disruption of the overland silk road by the Islamic conquests and Islamic domination completed by the 11th Century that lasted until the Mongol reconquest in the 13th Century was a source of dramatic global decline in commerce, knowledge and food supplies?
Did WWI and WWII have similar disruptive effects on commerce?