There can be no peace without an understanding of compassion. Compassion is the highest, most simple form of love. While we may not like someone, we can place ourselves in their shoes and offer them compassion for the fact that they are not so different from ourselves.
All sentient beings seek love and happiness. They all do their best to avoid suffering. At the basest level, we are all alike. The way we seek out these things and the exact things that cause either love or sufering are different for each of us. When we can understand and respect that diversity we can have peace.
We can choose to act from love and compassion or we can act from fear. Fear is what leads to violence and wars. To break that habit, we must begin to act from compassion. Acting from compassion is still acting. It means that when we act, we act from the courage of our convictions and with the intent to offer no harm to another but make the world a better place than it was before.