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.



I think there's a clear difference between testing it in areas where the fallout will affect a population, and intentionally ending the lives of 200K people in a flash.