Why are people in times of war willing to kill other people when they normally not do so?

In times of war, individuals may be driven to kill due to a combination of factors such as a heightened sense of loyalty to their country or group, dehumanization of the enemy, and the influence of Propaganda that frames violence as justified. Fear for their own survival and the pressure of conforming to the actions of peers can also play significant roles. Additionally, the chaotic environment of war can desensitize individuals to violence, leading them to act in ways they normally would not in peacetime.