The main focus of the League of Nations, established after World War I in 1920, was to promote peace and prevent future global conflicts. Created in an effort to foster international cooperation, the League aimed to resolve disputes through diplomacy and collective security. It sought to address issues such as disarmament, economic cooperation, and social welfare. Although it had some successes, the League ultimately struggled with enforcement and lacked participation from major powers, notably the United States. Its weaknesses paved the way for World War II, demonstrating the challenges of maintaining global peace through collective efforts.