[danieltillett]

Complex bureaucracies allow people to avoid personal responsibility for the outcome - the smaller your percentage contribution to the final decision the easier it is to disown the result emotionally (look at general elections to see this effect in action).

The other major factor is that many small steps are required to turn average people into killers. The military know this hence all the training to get soldiers to kill - it doesn’t take many months to train someone to pull a trigger, but it does take many months to get them to point a gun a person and pull the trigger. There is a fantastic book on this topic On Killing [1].

1. https://www.amazon.com/dp/B00J90F8W2/