The League of Nations, abbreviated as LN or LoN, was the first worldwide intergovernmental organisation whose principal mission was to maintain world peace. The League's goals included disarmament, preventing war through collective security, settling disputes between countries through negotiation diplomacy and improving global welfare.
Argentina, Australia, Belgium, Bolivia, the British Empire, Canada, Chile, China, Colombia, Cuba, Czechoslovakia, Denmark, El Salvador, France, Greece, Guatemala, Haiti, Honduras, India, Italy, Liberia, the Netherlands, New Zealand, Nicaragua, Norway, Panama, Paraguay, Persia/Iran, Peru, Poland, Portugal, Romania, Siam, South Africa, Spain, Sweden, Switzerland, Uruguay, Venezuela, Yugoslavia, Austria, Bulgaria, Finland, Luxembourg, Albania, Estonia, Latvia, Lithuania, Hungary, the Irish Free State, Ethiopia, the Dominican Republic, Mexico, Turkey, Iraq, the Soviet Union, Afghanistan, and Ecuador were involved.
United States never joined the League of Nations, and some relatively isolated sovereign states in Asia also did not join, including Saudi Arabia, Yemen, Mongolia, Nepal, and Bhutan.
The chief people responsible for the Treaty of Versailles were U.S. Pres. Woodrow Wilson, French Premier Georges Clemenceau, and British Prime Minister David Lloyd George. In an odd twist of history, the United States ended up not being part of the Treaty of Versailles.
The main reasons why the Germans hated the Treaty of Versailles was because they thought it was unfair. Germany had not taken part in the Conference. The terms were imposed upon Germany – when Germany disagreed, the Allies threatened to go to war again. The Germans were treated like a defeated country, but they did not think they had been defeated. They had signed an Armistice – a ceasefire – in 1918, and they had thought they were accepting Wilson’s 14 Points. In the event, few of the 14 Points got into the Treaty. The Germans thought they had been tricked and betrayed, and they hated the Treaty.
The short term effects of the Treaty of Versailles are that Germany had to accept guilt for starting the war, was forced to pay Allie's reparations, lost land, and had to reduce the size of its military. The League of Nations was created to settle disputes between countries before the military conflict. The Treaty of Versailles was essentially an attempt to weaken German's industrial and military machines following their attempted conquest in World War 1. The harsh sanctions and impositions put in place by the Treaty enraged the nation of Germany and eventually led to Hitler's uprising. Hitler used what he and the majority of Germany considered the harsh and unfair penalties levied against Germany to galvanize the nation and direct their ire towards the Allied nations and the Jewish people.