You do not achieve peace by cowering in the corner sucking your thumb. That only serves to encourage your enemies, and in the end, it only results in a more catastrophic war. Peace is achieved when the cost of waging war is so high, that no one wants to countenance it.
You have to discourage the elements of the world that seek to profit from war. They will always be there. You have to make them understand that waging war is a lost cause. Obama does just the opposite.