200k people were vaporized by atomic bombs in an utterly indiscriminate manner. This is inclusive of babies, little infants literally melted in a second. The radiation persisted decades after the blast.
We give it a special status despite conventional warfare still being capable of greater numbers, because of how exceedingly cruel and indiscriminate it is.
Historians described it as an 'ethical shock' and I agree with the term. If the yanks did not elect to exclusively melt civilians with their demonstration history might look at it differently.



more people die during America's Halloween celebrations per year than have been killed by Chinese police, in the entire country, in the same time period