This essay examines the establishment of the United Nations and the development of the Universal Declaration of Human Rights (UDHR) in the aftermath of World War II. It delves into the historical context, exploring the struggles for human rights and the question of their universality. The essay highlights the actions taken by the United Nations to promote international peace and security, including peacekeeping measures, preventive diplomacy, and counter-terrorism efforts. It also addresses the challenges and obstacles faced by the UN and UDHR in implementing universal human rights, such as wartime rape and conflicts arising from non-signatory countries. The essay concludes that while the journey has been challenging, the UN and UDHR have inspired policymakers and individuals worldwide towards a better future, continuing to strive for international peace and security.