Final answer:
The peacekeeping organization created after World War I was called the League of Nations. It aimed to facilitate global peace through collective security but was ultimately ineffective, leading to its replacement by the United Nations after World War II.
Step-by-step explanation:
League of Nations: The Peacekeeping Organization After WWI
After the conclusion of World War I, the League of Nations was established by the Treaty of Versailles in 1919 as the primary peacekeeping organization of the time. Its mission was to promote global security, maintain good relations between countries, and discourage aggression through the principle of collective security. However, the reluctance of the United States to join, due to the Senate's refusal to ratify the Treaty of Versailles, significantly hindered the League's efficacy. Additionally, the withdrawal of major powers like Japan, Germany, and Italy further crippled the League's ability to prevent conflicts. As a result, it was largely seen as ineffective, leading to its replacement by the United Nations after World War II.
The Allied powers recognized the need for a more effective international peacekeeping body, leading to the creation of the UN. The United Nations charter established mechanisms for peaceful settlement of disputes and collective action, including a General Assembly representing all member nations and a Security Council with permanent members holding veto power. This broad international cooperation aimed to prevent future wars and was a significant evolution from the shortcomings of the League of Nations.