Poland and Lithuania were two new states created by the post-war treaties. Vilna (now Vilnius) was made the capital of the new state of Lithuania, but its population was largely Polish. In 1920 a private Polish army simply took control of it.
Lithuania appealed for help. This was a crucial first 'test case' for the League. Both countries were members of the League. Poland was clearly the aggressor, though many people could see its case. The League protested to Poland, but Poland did not withdraw. The League was now stuck.
According to the Covenant it could have sent British and French troops to force the Poles out of Vilna. But it did not. The French were not prepared to upset Poland because they saw it as a possible ally against Germany in the future. Britain was not prepared to act alone and send troops right to the other side of Europe.
In the end the League did nothing. The Poles kept Vilna.
Upper Silesia, 1921
Upper Silesia was an industrial region on the border between Germany and Poland It was inhabited by both German and Polish people. Both Germany and Poland wanted control of it, partly because of its rich iron and steel industry. In 1920, a PLEBISCITE was organised for Silesians to vote on which country they wished to join. French and British troops were sent to keep order at the polling booths.
The industrial areas voted mainly for Germany, the rural areas mainly for Poland. The League therefore divided the region along these lines, but it built in many safeguards to prevent future disputes. It safeguarded rail links between the two countries and made arrangements for water and power supplies from one side of the border to be supplied to the other. Both countries accepted the decision.
Aaland Islands, 1921
Both Sweden and Finland wanted control of the Aaland Islands, which were midway between the two countries. Both countries were threatening to fight for them. They appealed to the League.
After studying the matter closely, the League said the islands should go to Finland. Sweden accepted the League's ruling and war was avoided.
One of the boundaries which had to be sorted out after the war was the border between Greece and Albania. The Conference of Ambassadors was given this job and it appointed an Italian general called Tellini to supervise it. On 27 August, while they were surveying the Greek side of the frontier area, Tellini and his team were ambushed and killed.
The Italian leader Mussolini was furious and blamed the Greek government for the murder. On 29 August he demanded that it pay compensation to Italy and execute the murderers. The Greeks, however, had no idea who the murderers were. On 31 August Mussolini bombarded and the occupied the Greek island of Corfu. Fifteen people were killed. Greece appealed to the League for help.
The situation was serious. It seemed like the events of 1914 which had triggered WW1. Fortunately, the council was already in session, so the League acted swiftly. By 7 September it had prepared its judgement. It condemned Mussolini's actions. It also suggested that Greece pay compensation but the money be held by the League. The money would then be paid to Italy if, and when, Tellini's killers were found.
Officially, Mussolini accepted the League's decision. However, behind the scenes, he got to work on the Conference of Ambassadors and persuaded it to change the League's ruling. The Greeks had to apologise and pay compensation directly to Italy. On 27 September, Mussolini withdrew from Corfu boasting of his triumph.
The Geneva Protocol
The Corfu incident demonstrated how the League of Nations could be undermined by its own members. Britain and France drew up the Geneva Protocol in 1924, which said that if two members were in dispute they would have to ask the League to sort out the disagreement and they would have to accept the Council's decision. They hoped this would strengthen the League.
But before the plan could be put into effect there was a general election in Britain. The new Conservative Government refused to sign the Protocol, worried that Britain would be forced to agree to something that was not in its own interests. So the Protocol, which had been meant to strengthen the League, in fact weakened it.
Two years after Corfu, the League was tested again. In October 1925, Greek troops invaded Bulgaria after an incident on the border in which some Greek soldiers were killed. Bulgaria appealed for help. It also sent instructions to its army.
The League condemned the Greek action. It ordered Greece to pull out and pay compensation to Bulgaria. Faced with the disapproval of the major powers in the League, the Greeks obeyed although they did complain that there seemed to be one rule for the large states (such as Italy) and another for smaller ones (such as themselves).