Now go back a couple hundred years, back to when cities were occasionally put to the sword, but that is beyond even this guy's memory.
WWI eventually defined total war, and no doubt its legacy was the primary reason France just surrendered to the Germans in 1941. The entire population had simply had enough.
Hell, Sherman was fighting total war in 1864.
https://en.wikipedia.org/wiki/Civilian_casualty_ratio#World_...
> According to most sources, World War II was the most lethal war in world history, with some 70 million killed in six years. The civilian to combatant fatality ratio in World War II lies somewhere between 3:2 and 2:1, or from 60% to 67%.
https://en.wikipedia.org/wiki/Civilian_casualty_ratio#World_...
From wikipedia:
"To maintain morale, wartime censors minimized early reports of illness and mortality in Germany, Britain, France, and the United States;[9][10] but papers were free to report the epidemic's effects in neutral Spain (such as the grave illness of King Alfonso XIII),[11] creating a false impression of Spain as especially hard hit[12]—thus the pandemic's nickname Spanish flu."
and
Investigative work by a British team led by virologist John Oxford[15] of St Bartholomew's Hospital and the Royal London Hospital identified a major troop staging and hospital camp in Étaples, France, as almost certainly being the center of the 1918 flu pandemic. A significant precursor virus, harbored in birds, mutated to pigs that were kept near the front.[16]
In some ways WW2 was the last of the wars of colonisation to be attempted. Assert racial superiority, a need for land, define the "natives" already occupying it as subhuman, invade and kill them, extract resources and colonise. This time in Russia since Africa was already taken and the Americas already liberated.