It certainly wasn't the pretext that the Wars of Religion heavily factored in the transformation from a more or less universal Europe with an HRE that actually deserved at least some parts of the name (long before Voltaire) to a continent with much stronger nation states, the idea of the nation itself was strongly influenced by the Reformation. And you can bet that this would not have happened if those wars had had a different outcome. The crusades were in part influenced by the fact that the diplomatic relationships between the European and the Middle Eastern nations, if you want to call it that, was pretty much non-existent. Another very important factor was the https://en.wikipedia.org/wiki/Battle_of_Manzikert that had occured shortly before. The Byzantine Empire seemed to be on the verge of collapse (in terms of C2C: They lost an important source of horses in Anatolia, and in this case the only horses capable to carrying the Cataphractes), and the Western nations hoped to help them out - originally - and of course to get something out of it for themselves. Had they succeeded, both the Western European nations and the Byzantine Empire could have benefited greatly. The pope hoped for two things in this complex: To gain safe access to the Holy Land for the pilgrims, and to regain influence in the Byzantine Empire, and not necessarily in that order. It is certainly not strictly about punishing people you consider to be guilty of something, and often times you prefer innocents. Besides, what do you mean by "racial slur"? We have had human sacrifices in many regions of the world, including Europe (the original tech quote about Druidism is very interesting in that regard). There is no connotation about different "races" when you say something about human sacrifice. "We" knew that being close to sick people could be a bad idea, but transmission via something like blankets is relatively new knowledge. In the middle of the 19th century (long after these times), the prevalent idea was that diseases were transmitted via foul air (https://en.wikipedia.org/wiki/Miasma_theory). Just what time are we speaking about here? Considering that more than 90 % of the original Native population in North America died before 1620 (by diseases), I didn't think you were speaking about the 18th/19th century here. Had this not happened, the European settlers might not have fared any better than the Vikings. I'm not an American. I think the Black Plague itself is a likely possibility. That would certainly explain the high fatality rate, although this one was even worse (about 90 %) than the Black Plague in Europe (about 30 %).