u/-Captain-Planet-

The standard textbook treatment of Sino-Roman contact mentions Gan Ying turning back at the Persian Gulf in 97 CE, the supposed embassy from "Andun" reaching the Han court in 166 CE, and the Roman trader Qin Lun at Sun Quan's court in 226. Beyond these famous episodes, how much sustained traffic was actually moving?

Specifically:

1. What do recent archaeological finds (Roman glass in Han tombs, Chinese silk at Palmyra, etc.) tell us about the volume of indirect trade?
2. Is there evidence that Roman administrators or generals ever encountered Han institutional practices via Parthian or Sogdian intermediaries — not "they had silk" but "they knew the Han state was doing X"?
3. Why did the Parthians work so hard to suppress direct contact, and how successful were they actually?
4. Are there any later periods (3rd–6th century CE) where the contact channel was meaningfully thicker than during the early imperial peak?

I've read Raoul McLaughlin's books and parts of Hill's translation of the Hou Hanshu. Looking for what current scholarship is doing with this beyond those.

The standard list of why the East made it through the 5th–7th centuries while the West collapsed usually includes: defensible Anatolian geography, sea-defensible capital with the Theodosian walls, denser urban network in the productive provinces, stronger fiscal base, weaker senatorial entrenchment.

All true. I'm interested in what's under that list — the specific institutional adaptations the eastern administration made that the West didn't.

Some I'm tracking:

• The theme system (later development but draws on earlier eastern military-administrative habits)
• The Christian charitable-medical complex (Basil's Basileias, the Sampson Xenon, eventually Pantokrator) as a new institutional form
• Tax collection through dioceses and bishops rather than only curiales
• The agentes in rebus and other inspectorate corps
• More frequent recoinage and fiscal reassessment

What else? Especially interested in cases where eastern administrators did something the West also could have done in principle but didn't try, or tried and abandoned.

Two related counterfactuals I've been chewing on, and I'd love specific suggestions from people who've thought about this seriously.

Counterfactual A: What's the most plausible package of technologies or institutional changes that, if adopted by the Western Empire by roughly 400 CE, could have meaningfully extended its life past 476? Not "Rome conquers the New World" stuff — I'm interested in things that already existed somewhere in or near the Roman world by the 4th century, and that the empire could have adopted with the administrative materials it actually had.

Counterfactual B: Suppose Justinian's reconquest (533–554) had actually stuck. Italy is devastated by 554, the Lombards walk in by 568; the Vandalic recapture was clean but the Gothic War was a 20-year catastrophe. What would have had to be different — by 530, say — for the reconquest to result in a durable restored western administration rather than a wrecked peninsula?

Candidates I've already considered (probably the usual suspects):

On the WRE side:

• Earlier and more systematic horse collar / nailed horseshoe adoption — better cavalry logistics against mounted opponents
• Han-style mass iron casting for cheaper plow parts and military hardware
• Counter-cyclical granary policy along Han ever-normal-granary lines
• Tax flexibility tied to environmental measurement (generalizing the Egyptian nilometer model)
• A reconstituted independent fiscal inspectorate, paid by the state rather than the audited province
• Faster legal-institutional integration of federate manpower into the command structure (rather than leaving Stilicho, Aetius, and the rest powerful but politically marginal)
• Drought-resilient cereals (sorghum, pearl millet) borrowed from the Garamantian Sahara and Aksum

On the Justinianic side:

• Some form of plague-response capability (the Justinianic Plague hits 541, mid-reconquest)
• Lighter-touch fiscal extraction from reconquered provinces — heavy tax pressure on a wrecked Italy contributed to the Lombard collapse
• A unified command structure for the Italian war rather than the Belisarius–Narses–John-the-Nephew rivalry that prolonged it
• Stronger naval garrisoning of the Western Mediterranean to suppress raiders after the Vandals were broken
• Faster restoration of Italian urban administration before the Lombards arrived

What am I missing? Especially interested in institutional changes (administrative, fiscal, military-organizational) rather than miracle-tech ideas. And especially interested in things that would help Counterfactual B — the Justinianic angle is less rehashed than the 5th-century one and probably the more interesting question.