In any form of competition or power struggle, when we win and others lose, it is only a matter of time before they strike back. The only situations that could truly work are those where everyone wins, because they are not built on a false economy, but on a movement of energy into a higher form.
Compromising is not the truth; it is each party giving up something to keep something they want. If your father stops communication and accepts compromise everyone will feel as if they have lost and are in sacrifice. As he continues to communicate and negotiate, and settle for nothing less than everyone feeling as if they have won, he brings a new integrity into the situation. All sides in this power struggle have at least some energy of truth, if not its form and he knows that. Joined together, they bring an integration of all perspectives into a new vision, which is, of course, what truth is.
I can only pray that both your parents will commit to communicating with each other until they reach a point of resolution, and achieved a new vision of truth a place where YOU win . Marie!!