Dehumanizing enemies can change soldiers until they dehumanize entire civilian populations.

Evidence

Dehumanization also operates at a broader social level. Among the reasons that Iraq veterans gave for opposing the war in Iraq was that it changed soldiers to the point where they began dehumanizing the Iraqi people (Hedges & Al-Arian, 2007). They did so by degrading and humiliating people at checkpoints, during raids on their homes, and in other aspects of their daily lives. — Albert Bandura, Moral Disengagement, 2418

Categorization

• XREF: Connects to vault claims on how ordinary people rationalize supporting dehumanizing policy; here the mechanism’s moral cost to the perpetrators themselves is shown. — connects to: Enemies are dehumanized into vermin before military force can be unleashed — Mark Fisher (edited by Darren Ambrose), K-Punk: The Collected and Unpublished…, 1451
• corroborated: 2 independent passages support this claim — Albert Bandura, Moral Disengagement: How People Do Harm…, 2418