No nation clinging to the current “waste is growth / landfill economy” will survive the emergent global polycrisis.
Identifying why the western Roman Empire collapsed in 476 AD has been a parlor game for at least two centuries, since Edward Gibbon published his monumental The History of the Decline and Fall of the Roman Empire (Abridged). Gibbon concluded Christianity had a major role in weakening the Empire, a view few today share.
Part of the fun of the parlor game is trying to identify the one thing that pushed it over the cliff: poisoning from lead pipes and wine goblets being a famous example that has been discounted by modern historians.
New research is more holistic, considering factors that were ignored or dismissed in the past, such as climate change and pandemics.
The word polycrisis captures this basic view: there wasn’t just one thing that toppled the empire, it was a confluence of crises that together nudged the empire to the breaking point. The empire was still robust and adaptive enough to handle any one crisis, but the onslaught of multiple, mutually reinforcing crises overwhelmed the resources of the empire.
The book The Fate of Rome: Climate, Disease, and the End of an Empire does an admirable job of explaining the polycrisis of reduced crop yields and pandemics.
Another approach is that of Peter Turchin and other historians, who look at social and economic cycles. Turchin holds that the overproduction of elites leads to elite conflicts that weaken the leadership and soaring wealth-power inequality undermines the social coherence of the state/empire. Ages of Discord: A Structural-Demographic Analysis of American History (2016)
End Times: Elites, Counter-Elites, and the Path of Political Disintegration (2023)
Historians such as David Hackett Fischer, author of The Great Wave: Price Revolutions and the Rhythm of History and Thomas Homer-Dixon, author of The Upside of Down: Catastrophe, Creativity and the Renewal of Civilization, examine the role of resource depletion, higher costs and diminishing returns for those doing the work of propping up the empire.
Historian Michael Grant makes the case for moral rot unraveling social coherence in his classic The Fall of the Roman Empire.
Having read all these works and many others on the subject, it seems clear that all of these factors were part and parcel of the polycrisis that brought down Rome. Each factor added to the empire’s already immense burdens while reducing its wealth and resources.
I would highlight three such consequential factors among many:
1. The depletion of the silver mines in Spain, fatally reducing Rome’s money supply.
2. The Vandals conquering the North African breadbasket of Rome in 435 AD. The loss of this major wheat supply doomed Rome to scarcities that could not be made up elsewhere.
3. The decline of trade with India through Egypt as silver and gold supplies diminished, as this trade provided 20% of all Imperial revenues. The Roman Empire and the Indian Ocean: Rome’s Dealings with the Ancient Kingdoms of India, Africa and Arabia
The view substantiated by Peter Heather argues that the Roman Empire was neither on the brink of social or moral collapse, nor fatally weakened by resource depletion. What brought it to an end were the barbarian invasions from what is now Germany and Eastern Europe. The fall of the Roman Empire: a new history of Rome and the Barbarians.
Heather argues Rome’s great success eventually led to its undoing, as the small, loosely organized Barbarian tribes learned from the Romans how to form larger, more cohesive and thus more powerful social and military organizations. Rome’s immense wealth was a magnet that attracted the Barbarians in two ways:
1. They wanted a piece of the rich Roman pie
2. In order to get that slice, they adopted Roman values and methodologies.
As a result of what they learned from Rome, the Barbarians became so formidable that Rome could no longer defeat them militarily, as they could when the tribes were smaller-scale and less cohesive.
Heather points out that late-era Rome faced multiple existential military threats, especially from the resurgent Persian Empire that Rome had battled for centuries. Despite its unwieldy size and bureaucracy, Rome managed effective adaptations that resolved the Persian threat.
Heather notes what other authors have focused on: Rome weakened itself by drawing an artificial distinction between “Barbarians” and “Romans.” Barbarians were anyone not within the Imperial borders, which were well-defined and defended, a point made by Edward N. Luttwak in his classic study, The Grand Strategy of the Roman Empire: From the First Century CE to the Third.
This distinction discounted the Barbarians and elevated the Romans, generating a fatal hubris in the Roman elites and squandering an opportunity to recruit the Barbarian tribes as stable allies. As with all human groups, if the rewards of alliance outweigh the risky gains of conquest, then leaders and their followers will pick alliance over conquest, the success of which is far from guaranteed.
So-called Barbarians became the core of the Roman army, and many of the most competent generals were either from the Roman hinterlands or they were Barbarians.
Rome had long exercised a military-diplomatic policy of defeating the Barbarians when they invaded Roman territories, but then making treaties with the Barbarian leaders that allowed the Barbarians to trade (and thus share the wealth) with Rome and settle within its borders.
In effect, Rome Romanized many Barbarian tribes over the centuries, mostly with “soft power” (diplomacy, sharing the wealth, cultural absorption) rather than “hard power” (military force).
