Stop derailing this is not about the atrocities of the allies in world war 2. First off the type of weapons don't matter, Colonial troops frequently did massacres on locals. Gas weapons are not that bad. Also here is a possible use.
en.wikipedia.org
Not Africa but it doesn't really matter.
So you know at the start of this conflict Putin did not plan to force the locals to abandon their culture, language, and customs? If Russia had gotten the land of Ukraine and it's population easily, the people would have probably been allowed to keep speaking Ukranian, as for customs how vague are you being there?
So it's ok for Putin to eliminate Ukranian state as long as the new subjects are allowed to speak their language? Also it does not matter, America was not a nation until the 18th century. If some group was able to destroy the military and kill millions would it be ok for them to forcibly break up the nation and prevent the people from voting for the territories to merge?