Thread by @AmesCG

Barbarian invasions didn't singlehandedly topple the Roman Empire, nor did (per Gibbon and other scolds) some too-narratively-convenient collapse of republican virtue. Instead, the fall of Rome was at least in part a supply chain failure.

A short thread!!

Starting in the mid-second century B.C.E., the Roman state provided free or subsidized grain to some subset of the population. Egypt began to supply most of that grain starting in the reign of Augustus.

Fast forward to roughly 400 C.E. and, while Egypt now supplies Constantinople, the Western Roman Empire still depends on grain from North Africa. Around midcentury, though, Gothic armies capture North Africa. Regular traffic of grain ships across the Mediterranean *to Rome* ends.

That has huge downstream consequences, as merchants also shipped trade goods along the state-created shipping network. Trans-Mediterranean shipping was expensive, so being able to tag one's wares along on a subsidized boat was a big deal. Like a premodern Eisenhower Interstate.

The short-term shock to Rome and the Roman economy of losing that trade network was profound and went far beyond the loss of the grain. Factor in warfare, and Rome's population collapsed within a few centuries. (Drawing on Wickham's "Inheritance of Rome," all errors mine.)

Trade networks eventually recovered, faster and in different ways than many used to believed. (Again, citing Wickham.) But the Roman grain trade represents another case of complex, interrelated systems being vulnerable to single points of failure.

Sound familiar?

All of this to say, if supply chain disruptions strike you as mundane, it most certainly is not. Trade networks define and make history! At the same time, blaming individual policymakers for breakdowns in complex systems is almost surely wrong.

nytimes.com/2021/10/15/pod…

Lastly, as an amateur I welcome of course thorough dissection by people who know more than me... (cc: @Patrick_Wyman)