It's a great analogy. Bitterness harbored in the heart of a person or a peoples is like drinking a glass of poison and saying to your enemy, "I hope this kills you."
Peace is difficult. It requires determination, confidence, intelligence and self-esteem. Yet, every person in the world would probably agree that if there was one thing that they could change it would be to stop pain, suffering and death.
Medical science works to prevent pain and end suffering. It works to accomplish the goal of peace in the body; health. Should we not always be working to end pain, suffering and death no matter how enormous the task may seem? In all things and into all situations; speak P-E-A-C-E.