. . . Arlington is a dedicated military burial site, so we know all the people there were soldiers at one point. The mass graves in the US that are like the ones in Iraq are these:
Civil War battlefields are vast unmarked graveyardsYou can't even put in a parking lot in the US without turning up a mass grave site from the Lincoln presidency, about half of them (the Confederates) were killed by Lincoln’s direct orders.
When citing the atrocities at Halabjah for instance, often omitted are the circumstances: There was a war going on between Iran and Iraq, the Kurds were on the Iranian side, and the Kurds were trying to secede from Iraq to form their own nation. Under that logic, Lincoln becomes a bigger mass murder than Hussein, and killing civilians at Halabjah was no different than the US bombing of residential areas of Baghdad.