Anatomy of Peace
If you are in a relationship of long-term conflict, read "The Anatomy of Peace." The main purpose of this book is to get the reader who is in conflict to reflect upon his own contributions to the conflict. Since our natural tendency is to blame the one we're fighting, we need to reconsider that our posture toward the situation and our "enemy" is a major factor. The longer we are in conflict, the more strongly we deny this, but it remains true.
We tend to objectify people instead of be at peace with them as people in relationship. We see ourselves as better (or worse) than them, or we have to be seen by them a certain way, or think we deserve better.
Instead, we need to apologize for what we can, sacrifice for our enemy out of empathy with them, give them space to thrive, and continue considering them from a perspective of peace.
The book does an especially good job dealing with skeptics, in the character of Lou, who assume this approach means compromising the truth or capitulating an important position. Being at peace with a person is different than giving them whatever they want. We don't have to be at war with people to maintain the truth or accomplish our goals.