Harms Inflicted vs Harms Suffered
People consider the harms they inflict to be justified and forgettable and the harms they suffer to be unprovoked and grievous.~ Steven Pinker (born:1954-09-18 age:61) The Better Angels of Our Nature: Why Violence Has Declined
Religion makes this effect even more pronounced. We are the God’s chosen people, they are devil-worshiping insects. Even if each side thinks it is inflicting equal pain for equal pain, it has actually ratcheted up the revenge spiral a notch. Further, the teach them a lesson effect requires inflicting double pain in revenge, which guarantees escalation.