--you're comparing incidences that later come to have independent verification I believe? the claimed mass graves found in Iraq, which ones are from the Iran-Iraq war? From the Kurdish repression of the 80's that the US supported (though the Kurdish repression in Iraq was nothing compared to that practiced by our ally the democratic Turkey...)?
Should we trust the US at its word that it is carefully following international protocols to determine the nature of these 'mass graves' or are they just throwing out numbers at us as they have in the past to justify war adventures? These are questions I think worth asking. I'd rather ask them than just trust the US propaganda machine.