Whenever there is war, there are serious disagreements between or among those who fight. One kind of disagreement is the contradiction in which two sides cannot both be correct. One is right and the other wrong. Then we have as a second kind of disagreement, what we call contrary views. Here, it is not necessarily the case that one is correct and the other incorrect. Both may have a partial truth. Thus, both may be wrong on some level and in different ways.
When groups insist that they are correct and morally right when this contradicts reality, and if this belief persists in the face of clear evidence against the position, we have a delusion. Delusions are part of the totality of war. Both sides can be wrong (in different ways) or just one side might be wrong and hold to a dangerous delusion that their own group is completely correct.
Forgiving others is one strong way of looking reality in the face and saying, “Yes, this person (or group) treated me (or our group) wrongly,” or “Now that I think about it, there is nothing to forgive because I cannot see how this person (or group) acted wrongly.”
Forgiving clearly is one way to break delusions that others deserve harsh treatment.
Forgiving clearly is one way to stop a war before it gets started if the aggressor can face his or her own delusions, see that others should not receive that aggression, and therefore stop acting on the delusion and aggression.
We need forgiveness in educational institutions when children are 4 years old. Forgiveness education needs to be part of instruction through the end of high school. Such education gives students the opportunity to grow up knowing how to look reality in the face, discern fair and unfair treatment, and stop the delusions, that can lead to war, before the aggression begins.