The United Nations stands as the principal global institution for international cooperation, with core aims and objectives centered on maintaining international peace and security, developing friendly relations among nations, and promoting social progress, better living standards, and human rights. Its structure is based on several principal organs, including the General Assembly, the Security Council, the Economic and Social Council (ECOSOC), and the International Court of Justice. An evaluation of the UN working reveals a complex and often contested record. In its peace and development perspectives, the organization attempts to link security with economic and social well-being, recognizing that lasting peace cannot be built amid poverty and injustice. However, its effectiveness, particularly in peace and security matters, is often hampered by the political interests of its powerful member states, most notably the veto power of the five permanent members of the Security Council. A significant and controversial aspect of the UN role has been the concept of humanitarian intervention. This refers to coercive action by states, at times with UN authorization, involving the use of military force in another state to prevent or end massive human rights violations, without the permission of that state. This practice directly challenges the traditional principle of state sovereignty and fuels debate about its legality and legitimacy under international law, a body of rules which is also adjudicated in part by UN-affiliated bodies like the International Criminal Court.