As long as we do not pray for our enemies, we continue to see only our own point of view – our own righteousness – and to ignore their perspective. Prayer breaks down the distinctions between us and them. To do violence to others, you must make them enemies. Prayer, on the other hand, makes enemies into friends. When we have brought our enemies into our hearts in prayer, it becomes difficult to maintain the hostility necessary for violence. In bringing them close to us, prayer even serves to protect our enemies. Thus prayer undermines the propaganda and policies designed to make us hate and fear our enemies. By softening our hearts towards our adversaries, prayer can even become treasonous. Fervent prayer for our enemies is a great obstacle to war and the feelings that lead to war.
Source: Seeking Peace