The notion of coexistence of nations and peoples has evolved in international affairs from "mutual understanding" into "international cooperation", then from "concord" into "entente", then from "dialogue of religions", particularly Islam and Christianity, into "dialogue of cultures and civilizations" and eventually from "respect for cultural diversity" into "alliance of civilizations". The process from "coexistence" to "dialogue" took decades during which the international community experienced two mechanisms of intergovernmental cooperation. The first was the League of Nations, founded shortly after World War 1, and the second was the United Nations, established at the end of World War 11