The Catastrophe, defined as the simultaneous destruction of almost all the Mediterranean cities around 1190 BCE, is taken as the end of the Bronze Age. It appears to have been the result of a military innovation.
Widespread collapse of civilization seems sufficient to cause trading networks to lapse.
If trade was falling off before that, it could be that the new iron swords coming out of northern Italy were driving down demand, and metal from the now useless bronze swords entering the market.
Hardly anything written for a few centuries after the Catastrophe survives, so the prospect of resolving the question seems dim.
You mean one of the causes, and there were many. Such as many failed harvests, big earthquakes in critical places along trading routes, migration (see above) that also caused warfare and more...
The astonishing nature of this revelation cannot be overstated. How did people in Turkey and Palestine, at the time the Great Pyramid was being built in Egypt 4500 years ago, know there was tin ore in England? How did people in England know anybody wanted it, a thousand miles away? There were no cities in between, no open-ocean sailing vessels. How did it even get across the Channel?
There was clearly a hell of a lot going on all over Europe and Asia that didn't need cities or books.
I don't know if finding cloves from the Moluccas in a middle-class house in Syria in 2000 BCE is more, or less astonishing.
