Once certain groups are stigmatized as evil, morally inferior, and not fully human, the persecution of those groups becomes more psychologically acceptable. Restraints against aggression and violence begin to disappear. Not surprisingly, dehumanization increases the likelihood of violence and may cause a conflict to escalate out of control. Once a violence break over has occurred, it may seem even more acceptable for people to do things that they would have regarded as morally unthinkable before.
Parties may come to believe that destruction of the other side is necessary, and pursue an overwhelming victory that will cause one's opponent to simply disappear. This sort of into-the-sea framing can cause lasting damage to relationships between the conflicting parties, making it more difficult to solve their underlying problems and leading to the loss of more innocent lives.