This article, after explaining the concept of peace building in the framework of United Nations peace operations, considers the challenges facing it. Peace operations are a complex and inter-related set of activities which lack clear legal status in the United Nations charter, but are accessible instruments for the maintenance of international peace and security. Despite the fact that peace building is a practical approach for the maintenance of peace and security and its positive achievements cannot be denied, it has been confronted with many challenges that diminish its effectiveness. These challenges relate to many factors, the most basic of which is global apartheid: an unjust international order. In addition, the belief also exists that it threatens a new form of western colonialism. In the framework of Western-based institutionalization, based on the liberalism that seeks to impose peace in other societies, it imposes peace without attention to their culture.