I think love is the key to true peace. Love carries us beyond hate, and brings man into the light of mercy and forgiveness, the 2 things we all need and are doomed without.
When we can love the enemy that is about to take our life, peace becomes internal and contagious. This is what Jesus did on the cross, and today we are still infected by those words, "Father, forgive them for they know not what they do".
Love is far more powerful than we realize, and
I Corinthians 13 sheds some deep light on the subject.
I think fear holds us back from true love, because we might end up embracing those we've hated in the past, and forgiving someone who has abused us.
And, the one wall that seems to come down when love is really in affect is Religion. This is just too much for some to bear, and so the wars continue.