The major international organization created in response to World War II to promote peace is the United Nations (UN). Established in 1945, the UN aims to prevent conflicts, foster international cooperation, and address global challenges such as poverty, health, and human rights. Its formation signified a collective commitment to ensure peace and security worldwide after the devastating effects of the war. The UN continues to play an essential role through various agencies like the World Health Organization (WHO) and UNICEF, shaping global policies and initiatives for a better future.