A member state is a state that is a member of an international organization or of a federation or confederation.
The World Trade Organization (WTO) and the International Monetary Fund (IMF) include some members that are not sovereign states; thus, neither organization ever speaks of "members states"; the WTO has simply "members" WTO members, whereas the IMF calls its members "member countries".
The League of Nations (abbreviated as LN in English, "La Société des Nations" abbreviated as SDN or SdN in French) was an intergovernmental organisation founded on 10 January 1920 as a result of the Paris Peace Conference that ended the First World War. It was the first international organisation whose principal mission was to maintain world peace. Its primary goals, as stated in its Covenant, included preventing wars through collective security and disarmament and settling international disputes through negotiation and arbitration. Other issues in this and related treaties included labour conditions, just treatment of native inhabitants, human and drug trafficking, arms trade, global health, prisoners of war, and protection of minorities in Europe. At its greatest extent from 28 September 1934 to 23 February 1935, it had 58 members.
The diplomatic philosophy behind the League represented a fundamental shift from the preceding hundred years. The League lacked its own armed force and depended on the Great Powers to enforce its resolutions, keep to its economic sanctions, or provide an army when needed. However, the Great Powers were often reluctant to do so. Sanctions could hurt League members, so they were reluctant to comply with them. During the Second Italo-Abyssinian War, when the League accused Italian soldiers of targeting Red Cross medical tents, Benito Mussolini responded that "the League is very well when sparrows shout, but no good at all when eagles fall out."
Between 1920 and 1939, a total of 63 countries became member states of the League of Nations. The Covenant forming the League of Nations was included in the Treaty of Versailles and came into force on 10 January 1920. The League of Nations was dissolved on 18 April 1946, when its assets and responsibilities were transferred to the United Nations.
The League’s greatest extent was from 28 September 1934 (when Ecuador joined) to 23 February 1935 (when Paraguay withdrew) with 58 members. At this time, only Costa Rica (22 January 1925), Brazil (14 June 1926), the Empire of Japan (27 March 1933) and Germany (19 September 1933) had withdrawn and only Egypt was left to join (on the 26 May 1937). The members (listed from earliest joining and alphabetically if they joined on the same day) at this time were Argentina, Australia, Belgium, Bolivia, the British Empire, Canada, Chile, the Republic of China, Colombia, Cuba, Czechoslovakia, Denmark, El Salvador, France, Greece, Guatemala, Haiti, Honduras, India, Irish Free State, Italy, Liberia, the Netherlands, New Zealand, Nicaragua, Norway, Panama, Paraguay, Persia/Iran, Peru, Poland, Portugal, Romania, Siam, Spain, Sweden, Switzerland, the Union of South Africa, Uruguay, Yugoslavia, Venezuela, Austria, Bulgaria, Finland, Luxembourg, Albania, Estonia, Latvia, Lithuania, Hungary, Ireland, Ethiopia, the Dominican Republic, Mexico, Turkey, Iraq, the Union of Soviet Socialist Republics, Afghanistan and Ecuador.