I'm doing research on the Nanking Massacre, and several authors compare the event to pre-modern wars and sieges. For example, Masahiro Yamamoto calls it an 'old-style atrocity'. Some claim that the opportunity for rape and loot was a motivation for many japanese soldiers during WW2, just like it was in the pre-modern era. Dan Carlin said something very similar in 'Prophets of Doom', which takes place around the siege of Munster during the reformation.
Link to Prophets of Doom: https://www.youtube.com/watch?v=WN8A4ygoEgo (The 'rape and pillage' quote is at 2:37:00)
My question is, how valid is this idea? Was the opportunity for rape and loot a significant factor in motivating troops to go to war during ancient or medieval times? And if so, is the comparison to what happened in China during WW2 a valid one?
It seems to me that it is, but I'm struggling to find any good sources on this.
Followup question: I have heard that "raping and pillaging" in this sort of context, as well as wonton destruction of infanstructure/leveling of cities in the was virtually unheard of, or at least less common in warfare in precolimbian Mesoamerica. Is that accurate?