What major international organization was founded after World War II to promote peace?

The major international organization founded after World War II to promote peace is the United Nations. Established in 1945, the UN was created to foster international cooperation and prevent future conflicts following the devastation of the war. It aimed to provide a platform for dialogue among member states and to address global issues such as security, human rights, and humanitarian assistance.

The League of Nations, while an earlier attempt at promoting peace following World War I, failed to prevent the escalation of conflicts leading to World War II, which is why it was replaced by the United Nations. The North Atlantic Treaty Organization (NATO), founded in 1949, is primarily a military alliance for collective defense rather than a peace-promoting organization. The World Health Organization (WHO), established in 1948, focuses on global health issues, which, while critical, does not specifically address the broader mandate of promoting peace among nations. Thus, the United Nations stands out as the primary international organization focused on maintaining peace and security in the post-war context.