For thousands of years we have tried war. Humankind now agrees that it doesn't work. Let's try peace for the next 500 years. If it doesn't work, we can always go back to the old ways. Ueido ga daisukidesu.
Peace is unavailable on Earth.
Peace lives only in our minds and God's Paradise, Heaven. There is a Heaven, and Peace presides there, and only there. The day we discover what Peace really is will be when we enter Heaven, or on God's Judgment Day. The concept of peace is not within humanity's reach. Humans are incapable of World Peace.