League of Nations, the association of countries formed at the end of World War I to prevent war and to promote international peace and security. It was designed as an agency through which nations might settle disputes and cooperate in matters of international concern. Headquarters were in Geneva, Switzerland. The League failed and was replaced by the United Nations after World War II.
The document called the Covenant of the League of Nations formed Part I of the Treaty of Versailles, which ended World War I. Most countries of the world joined the League, but many later withdrew. The United States never became a member of the League even though President Woodrow Wilson was its chief founder. Others who helped found the League were Jan Christiaan Smuts of South Africa, Viscount Cecil of Great Britain, and Léon Bourgeois of France.
During its early years the League settled a number of disputes and probably prevented several wars between small countries. It had the responsibility of administering the Saar Basin and the Free City of Danzig, which were taken from Germany after the war.
The League carried out postwar economic reconstruction and tried to protect ethnic minorities in several European countries. It also supervised the administration of colonies that had been taken from the defeated nations and entrusted to the victor countries as mandates. Efforts of the League to reduce armaments were unsuccessful.
Each member state had one vote in the Assembly but could have three representatives. The Assembly held one regular meeting a year. The Council served as the executive body, and usually met four times a year. At first it had four permanent members (Great Britain, France, Italy, and Japan) and four nonpermanent members elected by the Assembly. Later, when Germany and the Soviet Union joined the League and became members of the Council, the number of nonpermanent members was increased to 10. Either body might deal with “any matter within the spheres of action of the League or affecting the peace of the world,” but the Council was chiefly responsible.
Member states agreed that if any critical dispute should arise among them they would submit the issue to arbitration or to the League's Council. In no case were they to resort to war until three months after the award of the arbitrators or the report of the Council. If a member went to war in disregard of its obligations, it was to be regarded as having committed an act of war against all other League members. They were then to subject the guilty nation to a trade and financial boycott, but the Council might also recommend military action. These measures for forcing a violator into line were called sanctions.
This body was headed by a secretary general and staffed by several hundred persons from many countries. It did the League's clerical and administrative work, kept a register of all international treaties, engaged in humanitarian and health work, and tried to suppress the drug and white-slave traffic.
Article 14 of the Covenant provided for the Permanent Court of International Justice, or World Court. It was established at The Hague, Netherlands. The International Labor Organization was founded in 1919 in Geneva to improve labor conditions throughout the world.
During World War I, the Allies proposed several plans for an international peacekeeping organization; President Wilson proposed “a general association of nations” in his Fourteen Points. At the peace conference he obtained the adoption of the League Covenant as part of the Treaty of Versailles. But the U.S. Senate objected to the Covenant—partly out of isolationist feelings and partly because of politics—and rejected the treaty. The League came into existence in January, 1920, but was seriously weakened by the absence of the United States.
The League failed because it could not control the great powers. After Japan invaded Manchuria in 1931 the League condemned the aggression but did not impose sanctions. Japan withdrew from the League. In 1933 Germany withdrew and began to rearm. In 1935 Italy invaded Ethiopia and annexed the country. The League imposed economic sanctions but permitted Italy to get the supplies it needed most. Italy withdrew from the League. In December, 1939, after the outbreak of World War II, the League expelled Russia for its aggression against Finland.
In 1946 a final meeting of the Assembly dissolved the League. Its property was given to the newly formed United Nations.