If you're referring to the US presence in Afghanistan as an "atrocity", I'd say there' no similarity at all between the two situations. If you mean a specific "atrocity", it'd help if you'd indicate which one.
See: My Lai Massacre.
Those figures change, based upon the writer's resources: See website: My Lai Massacre.
us
It wasn't.
my lai
My Lai Massacre Hue Massacre Dak Son Massacre
"Four Hours in My Lai", by Michael Bilton and Kevin Sim (1993). Is a book about the 1968 My Lai massacre.
LTC Frank Barker
United States
347-504
My Lai
My Lai