Terms like rationalization and justification are vehicles for how good people do bad things and suffer no remorse. American pilots who have killed children in drone strikes or other bombing missions, may feel remorse or guilt, but that is quickly assuaged by justification, and terms like Collateral Damage. Those who bombed Hiroshima and Nagasaki expressed no remorse or guilt for their actions. We use war as an excuse to commit atrocities.
Think about the men who carry out the death sentences in this country. Few express remorse or guilt. Prime example of how taking away someone’s humanity is the first step in taking away their life, guilt free.
Please note, this is just my opinion. I am no arbiter of universal truth. I just know a little history, and history has patterns. One such pattern is genocide and mass atrocities. Call someone an enemy or criminal and their lives lose almost all meaning.
History also offers us a way out of the pattern, but we lack the vision and will to follow any other path.