Dehumanization
From civicintelligence
(1) Description of the pattern
One of the best ways to exploit and mistreat a population is to distance oneself from them as much as possible. We can justify our actions against others by portraying our enemies as sub-human monsters that deserve less that ethical treatment. By creating rigid us/them boundaries we can effectively establish that "we" are in the right, and "they" are dead wrong.