[Bayart]

>Now on the other hand, if Europe had suffered something like 50%+ death from American diseases while indigenous Americans suffered much lower death tolls from European disease - in other words, the reverse of what actually happened - then I figure that all bets would have been off.

The Black Plague killed off 50% of the population in quite a few countries and it didn't result in any invasion. I'm not sure the rationale stands without a technological imbalance as a basis.

[soapdog]

Because it also hit the Middle East, Asia, and Africa. Where would the invader come from? They were also dying of it too. In China alone there were about 40% dead according to recent estimates. The Black Plague was not restricted to Europe, it came to Europe and it wrecked nations everywhere. You can't have people invading, if these potential invaders are dealing with the same plague.

[Bayart]

>Where would the invader come from?

Poland ! I was alluding to the fact that the Plague wasn't uniform and that if demographic depression were an incentive to invade by itself, places that were unaffected (like Poland) would have expanded.

Instead Poland repeated the exact same pattern that had been pioneered in Gaul, then picked up by the Germans : expend East, where the Plague didn't have much effect, into non-Christian land and implement literate administration, centralized religion and feudalism.

The fact is the Black Plague didn't pose an existential threat in Western Europe, and it seems even else in other urban regions. I remember a historian, perhaps Le Goff or Leroy-Ladurie, remarking that the most astonishing thing about the Plague is that it changed nothing. The archives looked the same before and after. Just business as usual. In that sense the Thirty Years War was far more destructive.

All that to say that disease, as large as it gets, in itself isn't enough to sink well established institutions. And it's not a good enough argument to strip the Spanish of any credit in the conquest of the Americas.